Won't idle when cold / auxiliary air valve / idle air control valve

[davidgracevan]

-our van's engine has an ISC valve, when does this operate or turn on?

[timsrv]

There is an ISC VSV (Idle Speed Control Vacuum Switching Valve) that's controlled by the ECU. It's a solenoid operated air valve that when activated allows a small amount of air to bypass the closed throttle body valve. The result is an increase in idle speed of about 100 RPM. The ECU is programmed to complete the circuit (provide ground) to the ISC VSV when certain conditions are met. 12V positive is supplied to the ISC VSV from the AM2 ignition circuit when the EFI main relay is active.

[davidgracevan]

-thanks sir Tim, my ISCV was already missing, i want to restore it back, when do the ECU turns this ISC valve on?, in what situations do this ISC turn on?

[timsrv]

That's a secret :LOL2:, well, it sort of is. Toyota never bothered to talk much about this in the service manual so I'm not sure what these predetermined conditions are. They talk about the ISC VSV in the very end of the FI section, but there's only a simple schematic and a brief description on how to test it. I wish the manual would elaborate on this more, but it doesn't. Tim

[davidgracevan]

:LOL2: well i found this in the internet... http://www.autoshop101.com/forms/h26.pdf . based from what i read there, what i like to know is that do our ECU turns this ISC on when we shift the transmissin to Drive? coz mine RPM drops to 500-600 when shifting to drive or reverse... does it also turn on when for example theres a heavy electrical load?... what do you think sir Tim?

[timsrv]

As far as ECUs go, ours are some of the earliest (and most primitive) ones out there. When it comes to control systems it's all about input vs output. I don't think ours are sophisticated enough to detect electrical loads (but I could be wrong). I'm not sure what year range that article is referring too, but some of the standard functions in today's ECUs weren't even thought of back when ours were built. Tim

[davidgracevan]

-ok sir Tim thanks for your thoughts. You have an A/T van right?, do yours drops rpm when the gear selector is shifted to drive or reverse?

[theschnell]

FWIW, my rpms drop, somewhere close to the amount you mentioned, when I put my van in gear.

[theschnell]

Couldn't tell you how it was originally. Only had mine for just under two years now.

[davidgracevan]

-is it originally like that sir? RPM drops when shifting gear?

[davidgracevan]

-does the ISCV compensates the RPM lose when shifting the van in gear?... guys can i hear your experiences about this ISCV?... thank you :)

[davidgracevan]

-can anyone help me out here?.... thanks

[gushaman]

wow, tim doesnt even know what it does?!?!?!

[timsrv]

wow, tim doesnt even know what it does?!?!?!

LOL :dizzy:. I only know what I read in the manual (posted above). Whatever the manual doesn't cover becomes speculation. As far as I know the kind of "van specific" information requested isn't covered in any publications I know of. If anybody else has more information please post it here. Frankly, I don't think such information is necessary to correctly troubleshoot and repair the van, but it would be helpful for the troubleshooter/mechanic to fully understand the system. For me it's much easier to understand and troubleshoot problems when such information is available. I wish there was a van specific book that explained what was going on in the engineer's heads when they designed the system. I can get into that kind of reading :drool: (not sure what's wrong with me) :dizzy:. Tim

[davidgracevan]

-i'm just wondering sir Tim, does your van with A/T lose rpm when shifted into gear?

[timsrv]

Yeah, it's normal for the engine to slow down a bit when it has a load placed on it. I never really paid much attention to it so I couldn't tell you how much.......say 100-200 rpm??? The van I drive every day does not have a tachometer. Tim

[davidgracevan]

-ok sir Tim, it loses 200 rpm, if following the service manual, we should set it the idle at 750, right... shifting the gear, rpm goes down to 600-500 which i observed stresses the alternator because it is not turning at optimum speed especially during night time when it is really loaded, i just thought that it supposed to be the job of the ISCV but it turns out to be not. Some of our guys here suggested that idle should be set at 1000 so that when gear is shifted, it will at 750. i tried to set my idle at 1000, it makes the shiftshock a bit harsh... what do you think sir Tim?

[timsrv]

Set it at 750 while in neutral and forget about it. It's normal for our alternators to not charge while at idle. As long as it's not sitting at idle for extended lengths of time (with everything turned on) you will be fine. The system is designed to share the load with the battery. When it's at an idle the battery will help out with loads. When you are driving the alternator takes over and replaces energy that was taken from the battery......it's a give & take set-up. Of course this requires your battery to be in decent condition. If your battery is questionable then you may have problems. If the van needs to sit at idle for extended periods, then turn off the unnecessary loads. Tim

[davidgracevan]

-thanks sir Tim for that urgent reply. you hit it sir, during heavy traffics here, definitely i'll be sitting long at idle, another scene is the very slow moving traffic where you would just crawling and your foot stays at the brake pedal. my battery is new, checked every electrical concerns (keeping voltage drops in line acceptable) but i observed that when shifted to gear, you will notice a slight dimming of the lights, a/c blower somehow drops speed. what i do is to brake with left foot sometimes then put my right foot on the accelerator to raise the rpm back to 750 where everything is working very well. In newer vehicles with A/T, when shifted to gear, the ECU compensates the transmission load and raises the engine rpm back to the predetermined rpm, in our van that does not happen, like what you have said our ECUs a bit of a first age. i believe that the alternator still charges at idle considering before i change battery before, my old battery drops it voltage at 10 volts in the morning after parking at night, starting my engine helps it to bring back to 12 volts, but the rpm should be 750... what do you think again sir Tim?


(P.S. i'm really gald sir Tim that we were able to share our thoughts here :))

[timsrv]

Does the battery get too low to restart the van? Unless your battery is going dead it's nothing to worry about.

[davidgracevan]

-no it does not. i think i just worry too much sometimes. keep thingking of effeciency, i was planning to make something that will compensate for the rpm drop when in gear, somekind of added vsv in the engine which activates when gear is not in nuetral or park. oh well, thank you very much sir Tim.

[timsrv]

Keep in mind that higher RPM with vehicle stopped (and in drive) equates to additional energy loss due to drag and more heat/wear to the transmission due to increased slippage. Of course we're talking small amounts, but I think this would be more than enough to offset whatever benefit you may get from "electrical system efficiency". Bottom line is "if it ain't broke, don't fix it". Tim

[davidgracevan]

- thank you sir Tim for a reminder. i'm just trying to imitate the newer A/T s of toyota, studying how the toyota's ECT works, it could be applied to the van. innovating and trying to improve van's capabilities. i really love it so much. thanks again sir. i'll be posting if the plan was a success. :)

[gushaman]

i dont suppose there is an option for an under/overdrive pulley for our alts? i know some performance folks use larger or smaller pulleys to make things spin faster/slower. I do know the van alt has a small pulley

[timsrv]

I suppose if you were using the van for a purpose other than what it was designed for AND problems arose, then perhaps there would be merit for making changes. In my life there are enough problems to deal with that are urgent. Unless I ended up walking home I wouldn't consider this one of them.

Yes, you could possibly speed up the alternator. Then you have to wonder how fast is too fast? What if by messing around with it you traded a non-problem for a real one??? :doh: Just saying :lol:

[davidgracevan]

-thanks guys for the infos and reminders. i'm not just looking at the alternator's effeciency, i'm also looking at the engine's effeciency. studying our van's engine, it runs effeciently at 700-750 rpm, lower than that we can notice that it idles a bit rough, a noticable vibration will be felt, thats why i'm aiming to imitate the Electronic Controlled Transmission of Toyota in the newer vehicles to help the engine run at optimum, and also will help the alternator run at its optimum... theres no bad trade to see... as you have said sir Tim, our van's engine management is a bit primitive, thats why i'm trying to improve it by adding components that you can see at the newer age vehicles... :)

[mudrunner]

This was an interesting thread to read. Although I must say if you are looking to mimic what is going on in todays cars, it might be a better Idea then trying to make old work like new, just find a local junk yard (not u pull it or pick a part). They usually get autos that have been in wrecks and such, find one that hasn't been sitting long and is Newer model and do a swap i mean as long as you get the PCM and TCM you could just have a shop make motor mount adapters and voila you got a sweet modern engine.

[linnharding]

Now that I've installed a new TPS and adjusted the idle speed to 750 rpm when warm, my van runs and idles great except for one thing: when I first start it cold, it'll die if I don't hold the throttle open a bit for a minute or so. After that, all is well. Does this sound like a cold start injector problem? Or maybe a timer controlling the cold start injector? Advise on this would be much appreciated.

[timsrv]

Could be this, could also be a faulty air valve. In the FI section of the factory service manual there are tests for both of these. The cold start injector time switch is tested using an ohm meter. The air valve is tested by removing the hose (when cold) and trying to blow through it. It should allow flow when cold but prevent it when engine comes up to temp. Tim

[linnharding]

Thanks very much. I'll have a go at testing both of them. I'll let you know what happens .
Linn

[fuquan]

Thanks very much. I'll have a go at testing both of them. I'll let you know what happens .
Linn

Linn, did you get 'round to testing those components? I'm curious to know if you identified the problem.

[linnharding]

Thanks for following up. I'm embarrassed to say I haven't dealt with the problem. Throughout the summer, I only had to hold the throttle down for 10 seconds or so and that was just too easy. My trusty van isn't seeing much action these days since I got a 2000 Honda Insight. It needed a $25 dollar transmission input shaft bearing and I got the car for $1000 so this has become my main ride these days. 65 mpg is average, 75 if I work at it. I'll get back to my van soon and when it's fixed, I'll post it.
Thanks again for following up.

Linn

[Previa dude]

I have the same problem. its hard to start when cold. i have to step on the gas for about five seconds. Tim dose that sound like a cold start valve? i tested the ohms and it was 5.6. the books says between 2-4 ohms. could that throw it off by being 1.5 ohms over? i have not tested the timing switch for the cold start vavle yet. what do you think Tim?

[timsrv]

I see in your signature you only have a Previa listed........so I gotta ask are we talking a Previa or a van? If Previa, please post your question in the Previa Tech section. If you are asking about a van, then we're good. You should read through the FI section of the manual as it gives detailed answers to your questions. I'm a little confused with your terminology. When you say "cold start valve" are you talking about the CSI (Cold Start Injector) or the Air Valve? The CSI should have a resistance of 3-5 ohms. If I saw a reading of 5.6 I would say it's probably okay (Electrically anyhow........that doesn't mean it's not clogged or leaking).

Another component that affects cold idle speed is the Air Valve. The air valve is sandwiched between the two halves of the intake manifold. It should be partially open when the van is cold. You won't be able to visually see this when it's installed, but you can find out by pinching one of the tubes that goes to it. When the engine is cold, start it up and pinch a tube (best one attaches to the bottom side of the throttle body intake tube............it's the bigger one that goes towards the rear of the engine). Use a pair of long nose vice grips or something similar to pinch it off. When cold you should see RPM's drop with the hose pinched. If the RPM's are already low it may stall (this is an indication the air valve is good). If RPM's do not change then the valve is bad. After it warms up, pinch it again. This time it shouldn't drop but up to 50 RPM's is allowed. If RPM's drop more than 50, then the valve is bad. The electrical connector for the air valve is accessible from the front of the intake area below the cold start injector. When warm (about 180 deg) the resistance on it's terminals should be 40 - 60 ohms.

The Cold Start Injector Time Switch is mounted on the driver's side of the coolant filler neck. Here's a copy/paste from the manual to show how it's tested. Tim

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/Fuel%20system/Coldstartswitch_zps75556a30.jpg

[Previa dude]

Sorry about that Tim. I own only a Previa. It was however for my friends mom. She has an 88 le van with only 65k on it. I didn't think it was any thing major. It was just a clogged fuel filter. I guess it has never been changed all these yeas.lol anyways yeah one of the guys here at my job called the cold start injector a cold start valve. After looking online its an injector, so ill smack my friend at work for calling it a valve and making me look like a fool.lol

[mahleek87]

My van idles pretty rough in the cold when I start it up. Does any one have the part number of the idle air control valve? Im thinking about buying a new one from toyota and seeing if it makes the van run smoother.

[timsrv]

These are expensive and hard to replace so I would test and verify it's bad before replacing. It's Toyota part #22230-73011. MSRP is $281.17 or it can be purchased via a discount internet Toyota parts site for ~$200. www.rockautoparts.com used to have aftermarket ones until recently (probably sold out), but you can still get on eBay: http://www.ebay.com/itm/New-Kyosan-Auxiliary-Air-Valve-Toyota-Van-89-88-87-86-85-1989-1988-1987-1986-/130906693585?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AToyota%7CModel%3AVan&hash=item1e7aa59fd1&vxp=mtr. It's mounted to the underside of the top intake manifold & requires the upper manifold to be removed in order to replace. Tim

[coronan]

I don't believe my air valve is working. the van idles the same cold and hot. The 2 pins ohm out as good.


How much does the air valve raise idle when the van is cold, if its

4623

I want to eliminate it while my intake is off if its not working or not getting signal.
Anything to reduce the complicated plumbing and eliminate vacuum lines.


Thanks!

[llamavan]

When you start the van, does it run rough and want to die (or actually die if not given gas)?

Gwen

[coronan]

No but I have to floor it to make it start in less than 30 sec of cranking.
(probably a separate issue, Fuel safety switch or 5th injector.) happens regardless of summer or winter.

I need someone to squeeze their hose while the van is cold and see how much RPMs drop.

Part of this is evaluating if the air valve is worth having. (faster warmup is all its providing.)

I could rewire the AC idle up switch for a selectable high idle.

[llamavan]

Sounds like the aux air valve is working properly then; I would leave it alone. Unless of course you're willing to risk another problem (the one I referred to, and it's a pain) ...

Gwen

[coronan]

In the powered off state should i be able to blow through the air valve???

[isaiah44]

Not 100% sure this is related to the thermostat, but my 87 4x4 5sp has been idling really high once warmed up (after 5 minutes or so). It hasn't been overheating, and other than the constant sound of a revving engine when in neutral or the clutch is engaged, it's driving normally. A friend mentioned it could be a thermostat issue. Has anyone had this issue before?

[timsrv]

If the van warms-up and the heater blows hot air, then it's not related to the thermostat. It could be a failed air valve (between the intake manifold halves). When the coolant is cold, the air valve allows air flow (increases idle speed). When the coolant is hot, the air valve closes and prevents air flow (slower speed). To test, warm the van, then pinch an air tube going to or from the air valve. If the idle speed goes down, then you have a failed air valve. Tim

[isaiah44]

To test, warm the van, then pinch an air tube going to or from the air valve. If the idle speed goes down, then you have a failed air valve. Tim

Thanks Tim! I'll search for the air valve later this week. Much appreciated!

[spacecruisers]

If the van warms-up and the heater blows hot air, then it's not related to the thermostat. It could be a failed air valve (between the intake manifold halves). When the coolant is cold, the air valve allows air flow (increases idle speed). When the coolant is hot, the air valve closes and prevents air flow (slower speed). To test, warm the van, then pinch an air tube going to or from the air valve. If the idle speed goes down, then you have a failed air valve. Tim

don't mean to hijack but i wonder if my auxiliary air valve is bad (part number 22230-73011)? this is the part you're referring to right? I can't test because i already have the intake and exhaust manifold (and a bunch of other stuff) pulled right now and I'm just replacing everything in sight basically.

is there another way to test? I did notice that this past winter (my first winter with the van) it did idle very low on cold starts - treading the line very finely of cutting out. Would this be a symptom of a bad valve? Is there an aftermarket part available? looks like its NLA.

[timsrv]

The 87 van service manual shows how to test in more detail (pages FI-59 - FI-60). If you don't already have a copy, you can view/download here: https://drive.google.com/file/d/1q4u_5zlshRsVDv5v86CiukP7wOD7nKyF/view. If you're viewing that version, it's PDF pages 167 - 168. Tim

[spacecruisers]

The 87 van service manual shows how to test in more detail (pages FI-59 - FI-60). If you don't already have a copy, you can view/download here: https://drive.google.com/file/d/1q4u_5zlshRsVDv5v86CiukP7wOD7nKyF/view. If you're viewing that version, it's PDF pages 167 - 168. Tim

oh great, thanks tim. i always forget to consult the FSM first :doh:

this part looks NLA? any aftermarket? or just grab one at a pick n pull and pray it works?

heres a screenshot of those pages:

http://i.imgur.com/HWEmlPy.png
http://i.imgur.com/Mxc4iN0.png

[timsrv]

PS: Yes, it's Toyota part #22230-73011. They are spendy and a PITA to replace (unless you already have the intake apart). I've never actually had to replace one with new (was always able to find a good used one when needed). I see there's one listed on eBay: http://www.ebay.com/itm/Fuel-Injection-Idle-Air-Control-Valve-TOYOTA-OEM-2223073011-/322527770242?hash=item4b18273682:g:qTEAAOSw3gJZJcH F&vxp=mtr. You used to be able to get aftermarket ones off rockauto until just a year or so ago, but it appears now they are gone. Even those were expensive........just not as bad as OE.

The symptom of a bad one is having correct idle speed when cold but high idle when hot (if it's stuck open) -OR- having a low idle speed when cold, but a correct idle speed when hot (if it's stuck closed).

[spacecruisers]

PS: Yes, it's Toyota part #22230-73011. They are spendy and a PITA to replace (unless you already have the intake apart). I've never actually had to replace one with new (was always able to find a good used one when needed). I see there's one listed on eBay: http://www.ebay.com/itm/Fuel-Injection-Idle-Air-Control-Valve-TOYOTA-OEM-2223073011-/322527770242?hash=item4b18273682:g:qTEAAOSw3gJZJcH F&vxp=mtr. You used to be able to get aftermarket ones off rockauto until just a year or so ago, but it appears now they are gone. Even those were expensive........just not as bad as OE.

The symptom of a bad one is having correct idle speed when cold but high idle when hot (if it's stuck open) -OR- having a low idle speed when cold, but a correct idle speed when hot (if it's stuck closed).


ok perfect, i think that should give me enough info to troubleshoot after work and hopefully determine if its bad. id hate to have to pull the intake again seeing as I've already got it all torn apart right now :)

just saw that there was another thread on this (http://www.toyotavantech.com/forum/showthread.php?701-Won-t-idle-when-cold) so ill let this thread get back to its original topic!

[llamavan]

just saw that there was another thread on this (http://www.toyotavantech.com/forum/showthread.php?701-Won-t-idle-when-cold) so ill let this thread get back to its original topic!

Posts about Auxiliary Air Valve relocated to the pre-existing thread — THANKS for the heads-up and link, mistershmi !!! :thmbup:

Gwen

[Hammervan]

My aux. air valve has been bad for years, and while I have gotten used to having to turn up my idle speed in the winter and keep my foot on the gas while warming up (I've gotten really good at using the e-brake) I was waiting for an excuse to replace it and fix an exhaust manifold leak. That excuse has finally come (blown head gasket) but imagine my disappointment at learning it was NLA after waiting for years to fix it! I didn't see the eBay listing Tim mentioned but found another NOS valve on eBay that I was prepared to pay an exorbitant amount for, believing it was the last one in existence! I probably outbid someone else on this forum to get it. Sadly, the hoses that attach to the valve are also NLA (though one dealer's site tricked me into trying to order them) so unless anyone has a recommendation I guess I'll try to find similar hoses at the local auto shop. I don't think straight hose will be able to handle those sharp 90 degree bends.

[spacecruisers]

The one on eBay was an auction and was at around $30-40 when i bid on it with 30 seconds left. I bid it all the way up to $120-130 and still couldn't secure the max bid before the auction ended. I think someone had already set a really high max bid or had a bidding bot.... anyway it ended up going for almost $160. Not too bad I suppose for being probably the last brand new part in existence, but still more than I was wiling to pay, lol.

the hose won't fit those bends - I'm battling that issue right now. it kinks up badly. let me know how you end up figuring it out!

my aux valve MIGHT be okay, since i don't have to play the e-brake/gas game at stops like you do. it only happens on the initial warm up in winter. Even then it usually manages to stay just high enough to idle without dying, but it takes it a while to warm up as a result (unless i give it a little help, lol)

[timsrv]

Lol, I had a snipe bid of $150.01 on it. The snipe site I use is supposed to go max bid within the last 7 or 8 seconds of the auction. When I set my max price there was 7 hrs left with 2 bids and price was at ~$26. When I got home that night I was actually surprised to learn I wasn't the winner :doh:. I guess I screwed up earlier by telling somebody to go search eBay for one. Lol. Tim

[spacecruisers]

Yeah that was me, but i didn't get it either :LOL2:

Maybe someone here did! Whoever it was.... i will find you

[timsrv]

Lol, it was Hammervan. He mentioned it post #20 this thread. Tim

[Hammervan]

LOL, yup it was me that won that eBay auction. I figured anyone else that wanted it was probably on this forum but I didn't realize the competition was so fierce! I actually placed my bid before I saw this thread, so you can't blame me for whipping up the frenzy! My max bid was Toyota's original retail price since I figured that's what I would have had to pay if it was still available, and if I didn't get it I wasn't sure what I would do. I actually thought about bidding way more just to make sure! Obviously I need to get more high tech to ward off the snipers! It gets cold here in SLC so I'm excited to have a van that idles in the winter.
I got a few shaped hoses from the local auto parts store that should work. One is a 1/2" hose which is a bit snug but should get the job done.

[timsrv]

This guy on eBay still has 2 left http://www.ebay.com/itm/Fuel-Injection-Idle-Air-Control-Valve-TOYOTA-OEM-2223073011-/322527770242?hash=item4b18273682:g:qTEAAOSw3gJZJcH F&vxp=mtr, but I just can't bring myself to pay $285 for one. I would go $150, but any more, I'd rather take my chances with a good used one (I still have a few of those laying around). Glad I got all the molded rubber hoses when I did (now that they're like hen's teeth). It's a bummer when these type parts become NLA. I really wish I would have purchased a few more sets back when you could still get them. Tim

[Hammervan]

If that part was easier to get to I might have tried a junk yard one. The Dayco 80393 hose cut to fit will work to replace the NLA hoses (22233-73010, 22236-73011, 22237-73010), it's a bit snug (1/2" vs the 14 mm nipples). It's about a third of the price at Rockauto than my LPS, wish I'd found it there first:
http://www.rockauto.com/en/moreinfo.php?pk=960801&jsn=259

[timsrv]

Awesome! This is exactly the kind of information that makes forums worth while. FWIW, i thought these were 14mm, but didn't have one handy to measure. For vacuum, being a bit snug is better than being loose (no hose clamps needed). I just purchased a few of those for future projects. Tim

[originalkwyjibo]

FWIW, i thought these were 14mm, but didn't have one handy to measure. Tim
Oops! I mentioned the standard to metric difference in a different thread where this topic was recently discussed but incorrectly said they were 12mm. My only issue with the stretch fit was out of concern that they may split as they dry out and shrink from the heat. Of course I had alternate options at the dealer several years ago when I did my HG. I suppose it's a moo point now.
https://68.media.tumblr.com/tumblr_ly9qj4lk0a1qzef8lo1_250.gif

[spacecruisers]

Oh man, thanks Hammervan! I was about to just put the OEM's back on and try my luck. They were in decent shape but definitely older. I just ordered 3 sections of the Dayco 80393 hose that you linked to replace the 3 sections with the sharp bends.

BTW im in SLC too, so I'm going to hunt you down for taking my aux air valve :rol:

[Hammervan]

Oh man, when my aux air valve suddenly disappears from my van, I'll know who took it, mistershmi! I'll keep my eyes peeled for your van, I see a few still running around Salt Lake but they all seem to be 2WD. Glad the hose info was helpful.
Of course, now that I've replaced the hoses on the aux. air valve, including the 8 mm coolant hose, I've now noticed Tim's mention in another thread that it's best to use the original Toyota spring clamps and genuine Toyota hose for the coolant line. I used the same 5/16 fuel line hose and regular hose clamps like I did on my Hose of Death. Not sure if it's worth putting the original hose back on before I put it all together...

[Roger]

This guy on eBay still has 2 left http://www.ebay.com/itm/Fuel-Injection-Idle-Air-Control-Valve-TOYOTA-OEM-2223073011-/322527770242?hash=item4b18273682:g:qTEAAOSw3gJZJcH F&vxp=mtr, but I just can't bring myself to pay $285 for one. Tim

Just a heads up. I just tried to buy one of these with some expendable cash I had, to save myself tracking one down later if the part ever fails on my van, and they had to refund my money. They don't actually have them in stock and had to go to the dealer where they learned they were NLA. Said he would be removing the auction listing.

[timsrv]

Back when I used to sell there eBay required sellers to have physical possession of items before listing them. I guess that must have changed. I've purchased things from eBay before only to receive things drop-shipped from other locations. Next time I needed them I went right to the company who drop shipped and saved some money. I guess there's nothing wrong with sellers doing that as long as item arrives in a timely manner........just seems a bit fishy though. Glad you got your money back. Tim

PS: Funny how van parts just disappear from existence without warning. With the prices Toyota was asking I figured they'd be around for a long time. :doh: Tim

[Usaviator]

This is one of those stupid things you swear you can find, but then you get stuck on something. My mechanic has been doing quite a bit of work on my engine. Recently did a head gasket repair and when put back together realized engine was running rough. Since engine hasn't run in quite some time, he concluded that he thinks the problem is the fuel injectors, but upon working on them, all the injector connectors were deteriorating. Also he said the cold start injector connector and the IAC valve connector were deteriorated, and we have found pretty much every connector except for the IAC valve. Would any of you happen to know where I can find one? I've looked around Rockauto.com which has a pretty good selection of parts, but alas, no IAC valve connector. Or would anyone happen to know if these connectors were used on other Toyotas and/or different years and models? Even if someone has a picture of this thing, that would be very helpful. After this thing is done being worked on, I'm going to sell it, so stay on the lookout for a upcoming posting for an 1985 Toyota van that's had a ton of work done to it. Thanks for reading, all, and good luck.

[Usaviator]

My mechanic also just sent me these pictures. This is what we're working with.

5574

5575

5576

[Roger]

I had that same issue, and ended up replacing this and all the connectors under the hood.

For a lot of them — and I believe this one you are after is included — you can use this connector available from Parts Geek: http://www.partsgeek.com/catalog/1988/toyota/van/engine_electrical/engine_coolant_temperature_sensor_connector.html

They also stock them at O'Reilly Auto Parts, but I'm not at the shop where I have the part number handy.

If you look closely at the enlarged view of the photo, you'll see there is a notch in the plastic connector. For the coolant sensor it is in the center. For some of the other things that use it, like the IAC, the notch may be in a different spot. Since this was the only connector available that I could find and that was the only difference, I just made my own notch where needed to make it work. Hope that helps.

--

And if you need it, here is the TPS connector, which is a little different. http://www.partsgeek.com/catalog/1988/toyota/van/engine_electrical/throttle_position_sensor_connector.html

[llamour]

Hi all.

Newish '86 van owner and currently idling very rough upon starting (needs foot on gas or will sputter and stall). After warming up, about 3-5 minutes, things tend to smooth out. Recently had the fuel pump - which had died - replaced and my mechanic friend suggested replacing the air valve to assist with the early start idling issues. I'm looking for the part but haven't had much luck. Any suggestions on where to purchase an "air valve" as diagrammed above? Is "air valve" even the right name for the part?

Thanks! This forum has been a blast to read and refer...

[coronan]

I would look for vacuum leaks.

The air valve only provides high idle during warm up.

Mine never worked. And my van idles smooth.

Also try jumpering the fuel pump and see if that improves any thing. Not enough air flowing through the maf will make the fuel safety switch flicker. I have to step on the gas peddle a little to start my van. I little more air helps turn on the fuel pump.

Also check timing and fuel pressure.

[llamour]

Thanks for the response. My next move is to replace the fuel pressure regulator and check the timing.

[Hammervan]

I recently got the last new air valve in existence off ebay (as chronicled here http://www.toyotavantech.com/forum/showthread.php?701-Won-t-idle-when-cold&highlight=air+valve+ebay) and it made a huge difference in how my van idles when cold. I don't need to depress the gas when starting and keep it there until warmed up. It's an easy part to test and see if it's the culprit. I wonder if the air valve off another Toyota would fit, the ones I see at the junk yard look very similar, it would just have to fit in the small space between the manifolds unless you relocated it.

[Tan Van]

As far as ECUs go, ours are some of the earliest (and most primitive) ones out there. When it comes to control systems it's all about input vs output. I don't think ours are sophisticated enough to detect electrical loads (but I could be wrong). I'm not sure what year range that article is referring too, but some of the standard functions in today's ECUs weren't even thought of back when ours were built. Tim

I'm sure that this has all been learned since 2012, but, just in case this is new information ... here it is --

there are 4 types of isc vsv's listed here... the 4th one seems to be for the "on-off" control VSV that it says is for the 4Y-E engines...

apparently, among other things, there is an "Electrical load idle- up" mode


6209

page 10 on the pdf

[Tan Van]

There are 2 ways that the ISC VSV is shown to be plumbed...

the diagram we're all familiar with is as follows ...6557
here, the rear port goes to the throttle body

Now, for the other way...6558
here, my vacuum sticker ('87 2wd/auto/) clearly shows that the FRONT port goes to the throttle body---

if I'm not mistaken, this is a "one-way" valve, so, hooking it up backwards could be an issue...

for what it's worth, this valve's solenoid clearly clicks when my van is warmed up and i rev the throttle ...and my vacuum gauge shows "closed initially" , and, "open after solenoid click" (this is with the vacuum gauge hooked up to the rear/inboard port which leads to the big intake hose) ...
so..., obviously since the valve is receiving a constant vacuum pull at the hose from the throttle-body, I plumbed it as my sticker shows (on the front/outboard port)---

(I don't think it can go either direction like a BVSV)

I just want to know what's the right setup

[Tan Van]

okay... sorry if I wasted anyone's time... I just applied 12 volts to the ISC VSV and blew through the ports, and, it turns out that air flows in either direction when it's open, so, both diagrams for hose routing will work fine. On another note, I also find that, with the van warmed up and idling, turning on the lights has no effect on idle and does not open the VSV... So, it doesn't seem to be an "electrical load idle-up" feature...(I expected the electrical load to activate the valve and see an increase in idle speed similar to when you turn the steering wheel when parked at idle and the RPM's rise a little from the power-steering idle-up feature). However, when starting an already warmed up van and idling, the valve is initially closed, but, when I rev the throttle a couple times- the solenoid clicks and stays open (even when the engine returns to idle). So, I'm glad it works but I still kind of have no idea why it's there.

[isaiah44]

PS: Yes, it's Toyota part #22230-73011. They are spendy and a PITA to replace (unless you already have the intake apart). I've never actually had to replace one with new (was always able to find a good used one when needed). I see there's one listed on eBay: http://www.ebay.com/itm/Fuel-Injection-Idle-Air-Control-Valve-TOYOTA-OEM-2223073011-/322527770242?hash=item4b18273682:g:qTEAAOSw3gJZJcH F&vxp=mtr. You used to be able to get aftermarket ones off rockauto until just a year or so ago, but it appears now they are gone. Even those were expensive........just not as bad as OE.

The symptom of a bad one is having correct idle speed when cold but high idle when hot (if it's stuck open) -OR- having a low idle speed when cold, but a correct idle speed when hot (if it's stuck closed).

Hi Tim,

Is there a thread detailing the least painful way of removing/installing an idle air control valve? Mine is bad and I'm going to try to get one off a parts van this afternoon. Any help would be greatly appreciate.

Thanks!

[timsrv]

Sorry, no magic bullet here. That valve is actually bolted to the underside of the top half of the intake, so it has to come off before you can remove the air valve. Here it is in all it's glory:

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3259_zpst6qweov0.jpg

[isaiah44]

Sorry, no magic bullet here. That valve is actually bolted to the underside of the top half of the intake, so it has to come off before you can remove the air valve. Here it is in all it's glory:

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3259_zpst6qweov0.jpg

Thanks Tim,

The only description in the FSM that discusses access to this area is for a cylinder head removal, which includes opening the full engine compartment, draining the oil and coolant, and removing the exhaust pipe, throttle body, power steering pump, etc. Do you recall if all of that is necessary to access the idle air control valve?

Also, I found this while searching the web for the NLA part:

https://www.rockauto.com/en/catalog/toyota,1987,van,2.2l+l4,1279784,fuel/air,idle+air+control+(iac)+valve,6072

The part numbers don't match, but it says it's compatible with our vans. And it's cheap! Probably too cheap. There's only one left. Thoughts?

[timsrv]

That's not the air valve. There's a discrepancy regarding the aftermarket part manufacturers terminology vs Toyota's. We call that part the AC Idle-up Diaphragm. To find out more about it CLICK HERE (http://www.toyotavantech.com/forum/showthread.php?1582-What-does-a-particular-VSV-do-See-excellent-attached-diagram) and scroll down to the middle of the page.

You don't need to remove the cylinder head to remove the air valve. You just need to remove the top half of the intake manifold. Of course that's not quite as easy as it might sound. There's a lot of other little things that need to be removed before you can do that. You might want to read the Hose of Death thread (http://www.toyotavantech.com/forum/showthread.php?213-The-hose-of-death-thread) and cut an access hole in the back of the engine hump (as shown there). Having that access hole is an enormous help when removing the metal pipes from the back of the upper intake. Search the site for for more information on the other steps. Threads that discuss head gasket jobs should mention steps for removal of the upper intake. The information is here, the trick is finding it. If you're not having luck with the site search feature, use Google or other similar search engine (as talked about HERE (http://www.toyotavantech.com/forum/showthread.php?5323-Searching-TVT-successfully-and-posting-new-threads)). Tim

[isaiah44]

That's not the air valve. There's a discrepancy regarding the aftermarket part manufacturers terminology vs Toyota's. We call that part the AC Idle-up Diaphragm. To find out more about it CLICK HERE (http://www.toyotavantech.com/forum/showthread.php?1582-What-does-a-particular-VSV-do-See-excellent-attached-diagram) and scroll down to the middle of the page.

You don't need to remove the cylinder head to remove the air valve. You just need to remove the top half of the intake manifold. Of course that's not quite as easy as it might sound. There's a lot of other little things that need to be removed before you can do that. You might want to read the Hose of Death thread (http://www.toyotavantech.com/forum/showthread.php?213-The-hose-of-death-thread) and cut an access hole in the back of the engine hump (as shown there). Having that access hole is an enormous help when removing the metal pipes from the back of the upper intake. Search the site for for more information on the other steps. Threads that discuss head gasket jobs should mention steps for removal of the upper intake. The information is here, the trick is finding it. If you're not having luck with the site search feature, use Google or other similar search engine (as talked about HERE (http://www.toyotavantech.com/forum/showthread.php?5323-Searching-TVT-successfully-and-posting-new-threads)). Tim

Great, thanks Tim! I really appreciate the help!

[timsrv]

Absolutely not a problem :)>:. BTW, just thought I'd mention that AC Idle-up diaphragm is one of the few parts you can purchase from Toyota that's cheaper than aftermarket off of rockauto. Last time I needed one I found it on ToyotaPartsDeal.com (https://www.toyotapartsdeal.com/oem/toyota~diaphragm~sub~assy~idle~up~88606-28010.html) for $17.86 (I purchased 4 of them :)). Tim

[joegri]

wow this has been a great read for me. my poor van has been sitting for close to a year meaning I haven't used it much because I have a new job and don't use the van much. after reading the symtoms I believe my air vale is not working as it should. as usual Tim and the rest have help enormously with facts and pics.. thanx for that all. I spect I have a few bumping around in some Tupperware boxes and will replace it with one. I looked at what I thought will be an attack angle meaning I already have cut out a window in the firewall(hump) and should make this repair a bit easier. now just to be clear when I do start the van it runs just fine for maybe a minute then drops to idle then it just stumbles and rumbles and shakes after it does come to temp it runs kinda normal. think ill wait for a bit warmer weather and some extra time...did I mention its gonna snow here in Rhode Island this week! calendar says spring but I think thats a misprint

[timsrv]

I feel compelled to say this isn't a job I would recommend doing until AFTER you've performed the tests (discussed earlier in this thread) and confirmed it has failed.........just saying :wnk:. Tim

[joegri]

o yeah I agree completely Tim. there still is much to learn before I go in and start tearing. the good thing is I'm not pressed to use the van much these days so I'm of the school slow and steady wins the race

[isaiah44]

If the van warms-up and the heater blows hot air, then it's not related to the thermostat. It could be a failed air valve (between the intake manifold halves). When the coolant is cold, the air valve allows air flow (increases idle speed). When the coolant is hot, the air valve closes and prevents air flow (slower speed). To test, warm the van, then pinch an air tube going to or from the air valve. If the idle speed goes down, then you have a failed air valve. Tim

Hey Tim,

Is there some trick to testing (or getting to a hose to pinch)? I pulled an idle air control valve off a junked van and brought it to my mechanic with the FSM, but he insists there isn't a way to access any attached hoses to pinch to find out if the one already in my van is faulty. Instead, he says he somehow tested the ohms on it and decided it was functioning properly. Is that possible? I don't know what else would cause my idle to increase as the van warms up. Unfortunately, neither does he.... Any thoughts?

[timsrv]

Hey Tim,

Is there some trick to testing (or getting to a hose to pinch)? I pulled an idle air control valve off a junked van and brought it to my mechanic with the FSM, but he insists there isn't a way to access any attached hoses to pinch to find out if the one already in my van is faulty. Instead, he says he somehow tested the ohms on it and decided it was functioning properly. Is that possible? I don't know what else would cause my idle to increase as the van warms up. Unfortunately, neither does he.... Any thoughts?

Please refer to post #48 in this thread.

[isaiah44]

Please refer to post #16 in this thread.

Thanks. Has anyone had this issue with their van - idle continues to rise as the engine heats up and doesn't ever return to normal - and had it be due to something other than a faulty idle air control valve? My 87 won't pass smog bc the idle won't stay in an acceptable range and my mechanic says it's not the IACV, but doesn't have any other suggestions. Up against a wall here, any help would be greatly appreciate. Thanks!

[erik]

Hi all,

We are in process of getting our van registered in sunny California (originally from Manitoba, Canada) and we are being failed on our smog check because we had built our own replacement for the IACV when it failed years ago. The smog parts locator wants $180 for a "reconditioned" IACV, which seems ridiculous. The part number is 22230-73010.

We were wondering if anyone has a line on a 85 (or compatible) valve somewhere in the Bay Area or has an extra we could purchase.

Thanks!
Erik and Helena

[trestlehed]

Supposedly this part is NLA from Toyota.

Sometimes they pop-up on eBay. Otherwise might be a junkyard quest item.

< The smog parts locator wants $180 for a "reconditioned" IACV, which seems ridiculous.>
This might actually be a good deal if your van is your only vehicle and needs to be fixed asap.

Read this thread (if you haven't already):
https://www.toyotavantech.com/forum/showthread.php?701-Won-t-idle-when-cold&highlight=air+valve

Good luck!

[JPERL]

Hi all,

We are in process of getting our van registered in sunny California (originally from Manitoba, Canada) and we are being failed on our smog check because we had built our own replacement for the IACV when it failed years ago. The smog parts locator wants $180 for a "reconditioned" IACV, which seems ridiculous. The part number is 22230-73010.

We were wondering if anyone has a line on a 85 (or compatible) valve somewhere in the Bay Area or has an extra we could purchase.

Thanks!
Erik and Helena

Wow, These parts are pretty much extinct in the sense the IAC for the van is unique in that it is not shared with any other vehicle and so your best bet is scour the salvage yards assuming you can find any vans as they are now as rare as a hens tooth. Maybe eBay, although I just searched and found nothing. I would say if they sourced one for $180 grab it as its probably one the few left in the world because that is still less than what Toyota would charge if it was still available from Toyota.

Is the van idling high? if not, I am guessing it failed the visual inspection of the emissions test as a "missing component" and not that the Van was actually putting out higher emissions as a result of having a modified IAC? As long as you can set the idle at 850 or below that should be acceptable for passing emissions.

[erik]

Hi all,

Thanks for the replies. Yes, we are well within the emissions output limits (better than average!) and are failing due to "modified emissions control components". To be honest, I think that the whole visual check thing is a bit ridiculous, if I'm not polluting what should it matter what parts I'm using.

Anyhow, after some calling around I found an 86 at a junkyard near my work. Does anyone have instructions for how to get to the IACV? It's been years since I removed the original one from our van and I didn't put my replacement back in the same spot. I seem to recall needing to remove the intake?

Thanks,
Erik

[trestlehed]

Does anyone have instructions for how to get to the IACV? It's been years since I removed the original one from our van and I didn't put my replacement back in the same spot. I seem to recall needing to remove the intake?

Thanks,
Erik

Again, read this thread. The reason I linked to it is because it has pics and advice on how to remove it.

https://www.toyotavantech.com/forum/...ight=air+valve (https://www.toyotavantech.com/forum/showthread.php?701-Won-t-idle-when-cold&highlight=air+valve)

[MyToy]

Looks like my air valve is not working. Did the hose test and the idle goes down when I pinch it off with pliers when hot. Looking at the picture that Tim supplied from the manual and knowing I really don't want to pull the intake manifold off again and I don't want to spend that kind of money I may have figured a way to solve the issue.

Since the air valve is stuck in its open state with or without the power connector on it means that it is functioning as if the engine is warm all the time. So wouldn't it be easier to add an additional air valve in series with the original by way of an external valve control? The only difference would be that it would move to both states very fast rather than opening the door gradualy inside the original by way of the heater.
To trigger it would be very easy. It calls for a certain time before it closes for warm running conditions. I am not sure what that is but I can find out for sure. Then we us a small micro controller as a timer using the same power connector the old one used.

Anyone see any holes in this solution? If this works we would all have a solution for it.

Here is one valve I looked at.

https://shop.advanceautoparts.com/p/dorman-oe-solutions-vacuum-switching-solenoid-valve-911-606/10012203-P?navigationPath=L1*14932%7CL2*14982%7CL3*15307

I also spotted another valve in the engine I could not identify. I have attach a photo. It sits just to the right of the partition between the engine and the air cleaner. In the pic you can see it is just south of the clamp screw that holds the big intake hose.

Anyone know what this is for? Squeezing one hose changes the idle so it must have something to do with that.


Thanks

MT

[SoORYotas]

Looks like ISC VSV - IDLE Speed Controller. Excellent Thread titled 'What Does a particular VSV do?' listed as thread 1582. This thread has diagrams and several pages of discussion.

Cheers:wave1:

[xrs135]

I know it's a long shot... But does anybody have an extra auxiliary air valve sitting around (22230-73011) they'd like to sell me for a good cause?! 😁

[Jams]

If the van warms-up and the heater blows hot air, then it's not related to the thermostat. It could be a failed air valve (between the intake manifold halves). When the coolant is cold, the air valve allows air flow (increases idle speed). When the coolant is hot, the air valve closes and prevents air flow (slower speed). To test, warm the van, then pinch an air tube going to or from the air valve. If the idle speed goes down, then you have a failed air valve. Tim

Hi Tim, im trying to troubleshoot this part from my van also. I thought its opened and closed from an electrical signal, but what im getting from this (and the off vehicle testing method in the manual) is that its temperature sensitive and opens and closes based on the temperature of coolant flowing through it? Im a bit confused as to how it actually works. I “tested” my AA valve by hooking it up to a battery and nothing happened. When i was running the van last winter (never actually drove it) it idled low when cold and wanted to cut out, but seemed to get better as it warmed up. Any thoughts?
Thanks, James

[timsrv]

As with many things in the FSM there is some information, but not enough to completely understand function. This leaves a little room for interpretation/speculation, which I'll leave to you. Here's what I know:

The auxiliary air valve opens when cold and closes when hot. There is a "shutter" or "gate" inside that allows or disallows flow. There is a spring constantly pulling on the shutter/gate trying to close it, but there is a bi-metal "stop" preventing closure. There is an electric coil (heater) wrapped around the bi-metal stop and when 12V DC is applied it heats the bi-metal stop as to promote movement towards the closed direction. There is also coolant flowing through the valve body and when the vehicle is warm (approx 180°F) this also promotes movement towards the closed direction.

Is the electric heater coil by itself enough to close the gate? FSM doesn't go there, so I don't know.

Is hot coolant passing through the body enough to close the gate without power to heater coil? I don't know that either :cnfsd:.

If either method were enough, why would there be 2 ways of heating the air valve? When I speculate, I have to assume both are required to achieve complete closure (but don't know for sure). The only tests shown in the manual are to check continuity of the electric coil. They say to check it warm (176° F) and you should see 40 - 60 ohms. They also say to start the van and watch RPMs while alternately obstructing/allowing air flow. When cold you should see RPM's drop when obstructed. If hot RPM's should remain constant. The manual also goes on to say the valve should be slightly open at room temp (68°F). Of course you cannot check that unless you pull the intake manifold.

As with any moving part, after 30 something years of service it's easy to understand how things could get gummed up and fail. If the valve is removed and at room temp (68°F), when you look through the bigger air passage holes, the shutter/gate should be slightly open. When putting an engine together, since this part is NLA, all you can do is check physical condition, continuity, and look through the hole (at room temp) to verify it's slightly open. If the shutter is slightly open stick a scribe in the hole and force the shutter to full open, then verify spring pressure closes it back to the same spot it was before. As long as the travel is free/consistent, and assuming it passes visual and continuity tests, then put it back into service. If it fails any of those tests, then start looking for another one that will pass. Tim

https://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/emissions/air%20valve_zpsxtbwmlod.jpg

https://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/emissions/air%20valve1_zps5rknw7ak.jpg

[Jams]

Thanks for the response, Tim. Well written as always, haha. Looking at my air valve with the cover off, it appears the bimetal bar is warped towards the close position. The gate was slightly open at room temperature. I warmed it up with a hair dryer for a few minutes but didnt notice any movement. Maybe it just didn’t get hot enough. Next i might try throwing it in the refrigerator for a bit to see if it opens up. I tested the resistance and it was about 45 ohms at room temp. Im going to keep trying to figure this thing out, but if i cant then i might try rigging up a different kind of air valve from another toyota. Just a thought :)
Thanks! James

[VanDown]

I tested my air valve when I had everything apart for the HG. IIRC, the valve still appeared partially closed when cold, but I was able to see it close by pouring boiling water through the coolant line.

[Nash]

When you start the van, does it run rough and want to die (or actually die if not given gas)?

Gwen

Reviving an old thread here -- the quote above are the symptoms my van is experiencing right upon startup, so I was curious if someone could expand on what causes this as it seems to have been brushed over in this thread.

For more info: on cold starts, the van typically starts fine (sometimes with a sporadic RPM, but nothing major and no odd noises/feelings from under the hood), but once the engine is warm it will stutter with large RPM drops acting like it's going to stall out, though usually doesn't, and/or it will stutter and stumble to it's start. It also tends to idle low when warm. Once driving I have no issues. I read through this thread and this (https://www.toyotavantech.com/forum/showthread.php?2116-Stalling-RPM-dip!) one and this (https://www.toyotavantech.com/forum/showthread.php?1582-What-does-a-particular-VSV-do-See-excellent-attached-diagram) one, but am feeling a bit overwhelmed with all of the different valves and valve names and technicalities. I saw this (https://www.toyotavantech.com/forum/showthread.php?2698-Near-Stall-After-Start) thread which seems to be my same problem, but it had no information on it besides a possible FPR fix. Google tells me these symptoms are common to a faulty IACV (hence why I'm posting in this thread), but the info here seems to counteract that (also I'm not sure which one of the valves on our vans is the IACV :dizzy:).

Curious if anyone has had this same issue and successfully solved it? And/or could share some thoughts on what might be causing this? I recently cleaned my throttle body (which was very gunked up) as a first thought, yet the issue persists. It definitely seems to be an air-related issue to me, but I'm a newbie and could definitely be wrong.

[AntHamel]

When you start the van, does it run rough and want to die (or actually die if not given gas)?

Gwen

Hello, and thank you van gurus for this incredibly helpful thread. I’ve had ongoing cold start issues since I resurrected by 85 Van last year. I’ve narrowed it down to everything but this air valve. Cold start time switch is good (was replaced along with the Bosch connector), cold start injector passed ohm test and is confirmed to be working, I cleaned my throttle body when I did the TPS, I replaced all vacuum lines and verified there are no leaks, I even tried a spare ECU since I had one from the junkyard.

And still, when cold starting I got to put my foot on the throttle a little to get it to start. Otherwise, it’s exactly like Gwen describes here, I’ll hear it fire up but promptly die. I followed the on-vehicle check outlined on page FI-57 (that was quite a stretch with the longest pair of pliers I had) and it failed. No change in RPM.

So last night I pulled my intake and got the air valve out, and unfortunately it looks good, as illustrated in the repair manual??? Looks just like my other one, open just slightly at room temperature. Ohms are the same on both too, at 44.

I’m wondering if anyone knows a little more specifics about how these work. Like what’s the 7mm adjustment screw do? Does the heat coil change with coolant temp and then move the gate valve accordingly? If so then what is the actual electrical connector for? Or does it run off the ecu temp switch (which I have also replaced)? Lastly has anyone experimented with rebuilding these using parts from other Toyota air valves? I looked around online and it seems like other models had air valves just with different shapes.

I’m taking my fuel injectors to be cleaned and tested and I’m waiting on an intake gasket from rockauto, so I have a little while to figure out what I’m going to do. I would hate to put my new/old air valve in and have the same problem. Any input would be greatly appreciated, this forum has been a lifesaver.

[nobrush]

So I'm having this issue when I start my 1991 Previa. It would die if I didn't give it gas when cold until I set the idle up higher to prevent that. It can go up or down a bit (±200rpm) as I'm driving if I'm in neutral at a stoplight after it's warmed up but it works fine for now.

I took off the throttle body and cleaned it up as it was pretty dirty (cat safe cleaner), as well as removed & cleaned the ISC (I tested it with 12v and it seemed to open/close fine) & put on new gaskets for both. The problem is still there. I have replaced the fuel filter in the past when I had the issue before but I believe it was only an issue at stop signs since it's a manual and not idling low on startup like it is now. That was only a few years ago and it's a messy affair so I'm hoping to avoid that. I'm going to do a cap/rotor/wires/plugs tune up soon to rule that out since it's been 60k miles. (I'm at 407k miles!)

On a side note, I did pull a bonehead maneuver (I know really stupid) and pulled out the MAF sensor (or VAF sensor) which yanked on the "serviceable" soldering connections about 2 months ago. It wouldn't start at all and found this video showing me to pull off the jumper wires and just solder the pins straight to the board and it worked! I'm assuming that it has nothing to do with this issue as it ran fine for at least a month and a half before this issue popped up. This guy saved me a long drive to the junk yard. https://www.youtube.com/watch?v=CXCpYj-r_lI&t=714s