Injector(s) vs. Wiring vs. ECU vs. ??

[freeb]

Hey, Howzit? I think I'm about to remove the upper half of my intake in order to check my #3 and 4 injectors and wiring. Before I do that though I'd like to get some opinions and maybe some advice on what to look for, what else I might do while I'm at it or maybe a ''wait check this first.''

Here's what I'm looking at on my van which had been sitting for 10 years or so but had been running very strong for me for about a month. Good spark to cylinders and compression okay. (Double checked by mechanic). When I pull the #4 plug cap no change in running condition.
Sometimes #3 goes out also. Tapped on the bar that the injectors sit on and #3 kicked in.

The reason that I'm not sure I wanna pull the intake off to check the injectors and wiring is that when it started running on 3 cyl. (possibly 2) some weird things happened. First I had Christmas Lights.
Next my alternator belt snapped. Pretty sure after the dash lights came on. Though I realize they'd come on immediately once the belt snapped. Drove it a bit and it did get pretty hot enough to gurgle a few times but didn't let it up into the red.

It starts up easily. Runs on 3 cyl though I'm trying not to drive it unless I have to. It was really an all of the sudden type thing. Never had any hesitation. No fuel leaks (that I know of) Plenty of power.
Mechanic even strangely says that he didn't notice the injector problem until after he replaced the cat. He said it was running really well after replacing a belt and adjusting the throttle.
It was running on 2 cyl. when I pulled out of his shop. I'm pretty sure it was only on 2 or 3 when I brought it in. Don't know what to make of that.

Could this be an ECU problem? EFI relay fuse? Wiring circuit? Any way to check those with an ohm meter or volt meter? Most of the knowledge I have on motors has come from searching forums but I'm digging it. Actually glad to have something to work on now and I just moved into a place with a dry garage. :)

ECU looks okay on visual inspection but I think I remember an odd elec. type smell the morning it started misfiring. If I do need to remove the intake, what will I need and need to know? And as far as injectors? O-rings etc., I'd appreciate any help with where to get parts etc.

[timsrv]

Welcome aboard freeb :wave1:. Your problem can be any number of things, but Toyota's injectors are pretty tough and so are their ECUs. So IMO both of these would be low on the list of possibilities.......maybe the 2 very last things I would suspect. The improvement in running by tapping on the fuel rail seems to suggest an injector issue, but it could also be a coincidence. I'm not saying it isn't injector related, I'm just saying I'd check a bunch of other things before splitting the manifold and/or removing injectors.

My 1st question would be about trouble codes. Did you check for codes in your ECU? There may or may not be any codes present, but checking for them can often provide valuable clues, so anytime you experience a problem, codes should be checked before any corrective action is taken.

My 2nd question would be maintenance related. When was the last time you tuned up your van? Do you know how long it's been since the spark plugs, plug wires, distributor cap & rotor were replaced? If you don't know, then I would suggest replacing these parts 1st. Often times a miss can be caused by lack of maintenance. Even if the problem isn't here, if it's time anyhow then you've got nothing to lose.

Speaking of maintenance, when was the last time the alternator belt was replaced :?: ? Unless too tight or too loose, belts stay reliable for around 60k miles / 5 years, so having one break indicates incorrect tension, lack of maintenance, or both. Regardless, having multiple cluster lights come on at the same time usually indicates a charge system problem, so unless you're sure they came on before the belt broke, I'd just chalk it up to the broken belt. If this continues to happen after the belt is replaced, then I'd take look at your charging system 1st.

If you've had a recent tune-up and still have the miss problem, then the next thing you should check for is vacuum leaks. Pay particular attention to your air intake hose as these tend to crack near the throttle body. To verify it's condition, give it a good squeeze while the engine is idling. If the engine stumbles or stalls, then chances are you've got a cracked intake tube. You should also inspect all of your vacuum lines to make sure they are secure and in good condition. If all these look good, then the next thing to check is the fuel pressure. Other possibilities could be a failing ignition coil or a failing igniter, but these items are further down the list of likely possibilities. IMO, due to the access issue and the proven reliability of these injectors, splitting your manifold just to check would be way, way down on that list. Tim

[freeb]

Yeah, I just don't feel like its the injector itself. Thanks for the reply and info Tim. I haven't had the van for very long. Only a month or two.

Sorry, forgot to mention the codes. I was getting 21 and 51 for trouble codes. I put in a new upstream O2 sensor and its now giving me 51 only. Thats another reason I don't think its the fuel injector like my mechanic was suggesting. Only after me saying electrical a dozen times did he give in and say ''yeah it could be that.'' He wasn't aware of the code either.

I did do new plugs and wires just 100 miles ago while trying to pass emissions testing. Should mention that the #3 cyl had a spark plug that was about a 1/2 inch too short. Don't know what was going on there. Didn't get into the distributor. Wasn't having any misfiring at the time. Mechanic said its definitely not the distributor. He checked for spark and I did as well though I think I will double check. I may go ahead and do the cap and rotor like you suggest though.

There is a leak in the big intake hose by the throttle body. Put some glue on it temporarily. I was squeezing it before and it'd cut out and stall but a leak wouldn't kill a cylinder completely would it?

I can't find any other vacuum leaks but I do here hissing from the area of the EGR. Pretty sure its not just the hose. That normal?

I need to get this thing right. Its supposed to be my daily driver and I have a new job starting next week. :doh:

[timsrv]

Code 51 is almost certainly a bad TPS. Replacing it is pretty straight forward, but getting the correct adjustment is key. HERE (http://www.toyotavantech.com/forum/showthread.php?57-Engine-Service-Connector-not-working-can-t-set-proper-ignition-timing]HERE) is a good thread on testing and adjustment. The 2nd page has specific instructions that pertain to this.

Still, even though your TPS may be bad, it shouldn't create a miss. It would merely make the van sluggish and the fuel economy would go down. Vacuum leaks can create miss-like symptoms, but not always from the same cylinders. It concerns me a bit to hear you have a known cracked intake tube and have chosen a band-aid repair over replacement. I realize you may not have a lot of money, but these tubes are still available from Toyota for about $75 (and they last about 20 years). If you do the math, this is only $3.75 per year to completely eliminate this variable. If you can't swing the $75, there is always the salvage yards. Last time I got one of these at a pick-n-pull it only cost me $5 (and it looked almost new). Another thing you may want to re-check is the metal fitting that goes into the bottom of your intake tube. Did you take the tube off when you put the ":dizzy:glue:dizzy:" on it? If so, make sure you got the metal fitting and all of it's hoses back in the right places and secure.

Another variable to consider is the possibility of crappy aftermarket tune-up parts. I have no idea what brand stuff you purchase, but I'd like to point out the importance of high quality items here. Plugs, plug wires, cap & rotor should all be OEM quality (I prefer genuine Toyota). Getting the cheapest stuff in this area can end up costing you more in the long run (and sometimes even the "short run"). I have strong opinions about this because some of the toughest troubleshooting jobs I've encountered ended up being the result of poor quality tune-up parts. Sometimes a poor quality set of wires will work fine going to an OEM distributor cap, but if that cap is also poor quality, then the wires may not engage correctly and/or not make good contact. Sometimes just having new parts isn't enough, quality is an important consideration. Okay, so I'm ranting......back to the subject at hand........

When you pull the distributor cap, look for carbon build up on the inside where the conductors are. Also inspect the inside of the cap for eaten up conductors and / or any signs of moisture. You mentioned that your "mechanic" said the spark was fine. Did he happen to mention how he verified this? I'm guessing he just took a plug out and watched the spark jump on the electrode. This is always a good indication that spark is there, but by no means a way to verify the strength of the spark. Keep in mind that it's about 10X or so normal atmosphere inside the cylinder when the spark plug is firing. Just because a spark will jump at atmospheric pressure doesn't mean it will jump at 150+ psi. This is why I mentioned the possibility of a weak or failing coil or igniter.

At this point, before you do anything else you should check the inside of your distributor cap and the rotor......better yet to just replace these with quality parts. If the parts you've already replaced are of questionable quality, then you may consider replacing those again as well. If you still have your old parts you could always swap things around just to make sure. If you swap a part and the problem goes away, then you've most likely just stumbled onto the reason. Good luck and let us know how it goes. Tim

PS: Why was the cat converter replaced? If it was plugged up, it could very well have damaged your EGR and/or the modulator.

[freeb]

Just did new cap and rotor. No change. Everything is Napa. (not that I think that is the causing the misfire.) Since I already had Napa's wires in, I figured the cap should at least make good contact with the wires. Plugs are NGK. I did try the old wires plus testing them on an ohm meter. Continuity was fine. Also tried switching plugs around.

Toyota in Portland wanted around $118 for the hose. I do plan on replacing it but I'm going by priority. The dead cylinder is first on the list right now.

I do have other questions regarding the EGR, TPS plus a few other things but that's after the cylinder is undead.

Funny that you mention the fitting on the bottom of the intake tube. I swear the rear hose was off last time I got it back from the mechanic before I started playing with it. A small hose from the modulator to the EGR also.

No carbon on the distributor contacts. Some corrosion though. Rotor had corrosion too.

What's next? Is it possible to test the igniter and coil rather than just replacing?

Cat was replaced in order to pass emissions. I was way over (HC's 587, CO 2.0) and the mechanic I was using had gotten it very close to passing after it running extremely rich. It was a little over in everything first time around then the numbers doubled for the next test. He said that he had cheated the test the last try (6th) before doing the cat. I'd love to know what he meant by cheating. Don't know if he caused other problems.:cnfsd:

[freeb]

Found in the manual how to test the ignition coil. Primary tested at 0 ohms with my old skool multimeter. (the type with the needle. moves from left to right with zero to the right of scale.) Manual says it should be between 1.2 and 1.5. Secondary tested at 8.2. which is in the the acceptable range of 7.5 to 10.5. Tested while cold. Am I in need of a new ignition coil?

[timsrv]

That's funny he replaced the cat due to a failed emissions test, but didn't replace a bad TPS? If everything else is dialed in, these vans will pass the test even without a cat. Cats do make a difference, but not nearly as much as some of the other emissions related parts do. Some mechanics will recommend priorities based on their profit margins.......are you sure this isn't what's going on here? The air intake tube is Toyota part #17881-73020 and is available for $71.22 at 1stToyotaParts.com (https://www.1sttoyotaparts.com/oempartscat.html]1stToyotaParts.com). Of course they will also want $9.95 shipping though. You might try Tonkin Toyota in Portland and ask them if they will match 1stToyotaParts.com's price........more often than not they will do it.

As for the coil and the igniter, I can tell you that having a coil fail is not uncommon. Igniters can fail too, but do so far less often than the coils. I don't know if your coil is good or bad though. An analog meter may not be sensitive enough to tell the difference between 1.5 ohms and 0??? Many meters are not capable of that. When I get stuck on an issue like this I usually double check by swapping parts from my parts vans. It's kind of sloppy troubleshooting I guess, but it's usually quicker and easier than doing it by the book. I realize not everybody has that luxury, but there is always the pick-n-pull. to be honest, both times I've had coils fail I never actually changed them. Both times I just grabbed an extra distributor and stuffed it in there.........and I experienced instant gratification :sfr:.

Napa usually carries pretty decent tune-up parts, so you're probably okay there. The fact that you swapped stuff around should pretty much rule out the possibility of these parts being bad. I don't know of any test for the igniter. Even the Toyota service manual states "try another igniter" rather than give a testing procedure.

Have you pulled your plugs out after running to see if they are wet with fuel? If so, then it's almost certainly an ignition issue. If not, then perhaps you should go back to looking at the injectors.

I really hate to tell you to replace your coil or igniter without knowing if that's the problem, but you're running out of other things. I would probably do a fuel pressure test before swapping any more parts, but if that were the problem, it would be more pronounced at higher speeds (when the demand for fuel is higher). But that isn't what's happening here.........is it?

Without hands on it's tough to troubleshoot. I'm running out of advice so I hope you find it soon. Good luck and let us know what you find. Tim

[freeb]

Thanks for the help so far Tim. I know its tough to diagnose something like this without being there. Thoughts and opinions are definitely appreciated though. I'm starting to think that my problems are worse than I was originally thinking. But I've already put well over $1K into it and.... I just like the thing.

Installed the new ignition coil. Started up on 3 cyl then began running on 2.
Rented a compression test gauge because I just don't trust the mechanic I was dealing with.
Warmed it up as best I could. My temp gauge won't go any higher than about 1/4 way to H since my alt belt snapped and it got pretty hot a few times. Maybe a bad thermostat? Radiator light has been coming on and off too.

1st test read 130 psi on 1, 135 on 2, 130 on 3 and 110 on 4. So I was thinking ''bad valve:cry:''.
Tried testing #1 again right after and i got around 80 psi instead of 130 like the first reading.
:cnfsd:


Drove it some more thinking maybe it cooled down too much in order to accurately test again and I got 80psi for #1, 70 for #2, 85 for #3, 75 for #4. I'm baffled by that.

A couple other things to note:
1) smell of gas after shutting off.
2) 1st and 2nd plug are dry. 3rd plug wet and smell like gas. Oily sludge on the top of thread near tip. Not the spark area. 4th plug same as 3rd.
3) smoke coming from #1 cyl after pulling plug and driving around a while. That normal? Cylinder just working too hard?
4)Terrible gas mileage.
5)Ticking sound.
6)Misfire and stumbling goes from bad to worse when put into gear.

***7)Runs on 4 cylinders for the first second after starting if its been sitting a while. (this seems like an indication of something. Just don't know what.

I would agree that the mechanic wanted to sell me on the cat. I had him do the exhaust manifold and just stuck with him. Tough to find a good mechanic when there's so many to choose from. EGR and TPS are next on my list if I can repair whats going on now without breaking the bank.

Doesn't seem to be an issue with demand for gas at higher speeds. Never noticed that when it was running smooth either. Thanks for the info on the Intake Hose. $80 isn't too bad. Glue was bad. Duct tape for a quick fix but glue?

[NEC]

I have a couple of used air hoses I've been stockpiling. I can let one go for 20 plus actual freight if interested. Obviously, these are not new, but in good shape and still somewhat flexible. PM if interested and I will send you a proper invoice.

[Bala]

I just had these same two codes until a few weeks ago. I humbly recommend you start by removing your air intake hose and check for cracks/leaks. If you're on a tight budget, get some good high temp silicone to fill in/patch up any cracks. This will hold together for a long while until you can afford to replace with a new hose.

Before putting the repaired or new hose on, remove the throttle body and clean it good with 1-2 bottles of throttle body cleaner. Do not be soft of this application. Clean out the passages, especially the EGR passage located just on the lower right side inside the plenum. Thoroughly clean the throttle plate.

Before putting the throttle body back on, follow Tim's instructions on replacing the TPS...to the T. Do not over torque the setting screws for it can throw the TPS out of spec. Once you then reinstall the throttle body with your new TPS, check to make sure the specs are still on. The slightess nudge can through it out of spec.

Then, make sure your base and advance ignition timing is dead on.

Also, replace your O2 sensor if needed. You can get a universal aftermarket O2 sensor for around $50. Autozone also has a TPS made in Italy they can order for you for $70-80 if you don't want to pay the +$100 from Toyota.

Good luck!

[freeb]

Thanks for that info. The short term fix on my intake hose has been some rubber safe glue. Hack, I know. Thanks to NEC, I'll have one that I can be sure has no leak. :) I'm going to Napa today for a new PCV valve and grommet and will check if they have a decent TPS. If not I'll put in the order with Autozone.

I was planning on checking my TPS operation by disconnecting the harness and seeing if there'd be any change in running condition. (ie: cylinders start firing again.)
Found it to be already disconnected.:no: The connection doesn't click and secure as it should.

Anyway, plugged it in and no change. Still starts up on all 4 then 1 second later its on 2 cylinders. Maybe the tps is bad? Hard to believe that it could kill cylinders though.

On a side note, my Brother in Law who is a mechanic/dealer in Japan suggested the Cold Start Injector or Water Thermo Sensor among other things. Anybody think I could at least rule that out? I tested the Water Thermo Sensor and it was okay. Cold Start Injector Timing switch readings were off. My multimeter went out on me while testing at the ECU so anymore voltage and ohm reading checks are on hold. Hoping its the fuse. :cnfsd:

Tried spraying carb cleaner around the intake gasket and no change.
****I keep forgetting to mention this but my Temp gauge is only rising about 1/4 of the way at most.**** Radiator light is on also. Mechanic said its probably t-stat. Dunno.

[llamavan]

Temp gauge at 1/4 might be normal. Most vans run around 40-45% +/- on the gauge, but a minority are perfectly normal outside that range. I know one guy whose van is totally normal at 75% (scary!); Skylervan is totally normal at 25% (in fact, over 50% is minutes from overheating, and if I'd known that 45% wasn't normal for him when I bought him, I would have saved myself the expense of a head job).

The "radiator" light is supposed to tell you when the reserve tank drops below the "add" line. So check the reserve tank first.

IF the level is OK, something about the switch wiring is faulty (and it would be a darn good idea to fix it once your other problem is under control because every bit of valid information about anomalies in the cooling system is vital to keeping your van alive). The switch is NLA and the grommet between switch and reserve tank only came with the switch, so DO NOT remove the switch from the reserve tank!!! For now, you can get the light to go out by unplugging the reserve tank switch itself. Click here (http://www.toyotavantech.com/forum/content.php?200-Change-your-alternator-ILLUSTRATED!) and reference the second photo.

Gwen

[freeb]

That's good info on the temp gauge, thanks. It was running around 40-45% for the 1000 miles or so I'd put on it since I've had it until the alt belt snapped and it came real close to overheating. Now its doing the 20% or so thing. Weird...

Anybody know if its possible to use a matching ECU from California with a non California van?

[mrkt4]

Welcome aboard freeb :wave1:. Your problem can be any number of things, but Toyota's injectors are pretty tough and so are their ECUs. So IMO both of these would be low on the list of possibilities.......maybe the 2 very last things I would suspect. The improvement in running by tapping on the fuel rail seems to suggest an injector issue, but it could also be a coincidence. I'm not saying it isn't injector related, I'm just saying I'd check a bunch of other things before splitting the manifold and/or removing injectors.

My 1st question would be about trouble codes. Did you check for codes in your ECU? There may or may not be any codes present, but checking for them can often provide valuable clues, so anytime you experience a problem, codes should be checked before any corrective action is taken.

My 2nd question would be maintenance related. When was the last time you tuned up your van? Do you know how long it's been since the spark plugs, plug wires, distributor cap & rotor were replaced? If you don't know, then I would suggest replacing these parts 1st. Often times a miss can be caused by lack of maintenance. Even if the problem isn't here, if it's time anyhow then you've got nothing to lose.

Speaking of maintenance, when was the last time the alternator belt was replaced :?: ? Unless too tight or too loose, belts stay reliable for around 60k miles / 5 years, so having one break indicates incorrect tension, lack of maintenance, or both. Regardless, having multiple cluster lights come on at the same time usually indicates a charge system problem, so unless you're sure they came on before the belt broke, I'd just chalk it up to the broken belt. If this continues to happen after the belt is replaced, then I'd take look at your charging system 1st.

If you've had a recent tune-up and still have the miss problem, then the next thing you should check for is vacuum leaks. Pay particular attention to your air intake hose as these tend to crack near the throttle body. To verify it's condition, give it a good squeeze while the engine is idling. If the engine stumbles or stalls, then chances are you've got a cracked intake tube. You should also inspect all of your vacuum lines to make sure they are secure and in good condition. If all these look good, then the next thing to check is the fuel pressure. Other possibilities could be a failing ignition coil or a failing igniter, but these items are further down the list of likely possibilities. IMO, due to the access issue and the proven reliability of these injectors, splitting your manifold just to check would be way, way down on that list. Tim


and do not overlook the injector conn ends that falll apart/ and your gas tank is more than likey full of rust if has been sitting for 10 years.

[timsrv]

Hey Freeb, Sorry about the late response. I've been working a job out of town since Tuesday and just returned (no internet access there). It's good to see others are chiming in here with good advice :thmbup:. I had a few questions about the compression test, like how you did it, but then I found that there's a few good videos on youtube that explain it well. Here's a good one: http://www.youtube.com/watch?v=X_tbksFYhl4&feature=related . Go ahead and watch that to make sure you were doing it right. If you weren't, then the test doesn't mean much. Here's one that shows the test being done on a van (Click on the photo to view......not sure who that handsome guy is :)>:)
http://i8.photobucket.com/albums/a23/timsrv/th_MVI_0695.jpg (http://s8.photobucket.com/albums/a23/timsrv/?action=view&current=MVI_0695.mp4)

If the plugs are wet and smell like gas, then it's not likely injector or injector connector related. Tim

[freeb]

Ahh, thanks for those video's.:) First thing I noticed, was that the gauge needle should stick at the highest reading. The gauge I borrowed isn't doing that. It drops immediately after each turn of the engine. Very hard to get a reading off.

But that makes me wonder if its a problem with the gauge or is something going on like a blown head gasket???

I'm also wondering if its too late to be draining the gas tank. Its been run down toward empty a few times already. Rust may have done its damage but hopefully it wouldn't have gotten past the fuel filter?

I'm going to hold off on installing the new TPS I just picked up from Toyota.

BTW, thanks NEC, just got the hose delivered as I was typing this. A lot more plyable than the one I had.

[timsrv]

Sounds like the compression tester you used was defective. There is a release valve on the side of the gauge that traps the pressure until you're done testing. After recording results you release pressure and and move on to the next cylinder. I don't know how much $$$ compression testers go for these days, but the one in my video only cost me about $20 at my local parts house.........of course that was about 20 years ago. Even with todays prices I can't imagine a simple one like mine costing more than $40. I also have the expensive Snap-on compression testing set, but I actually prefer this one, so the Snap-on set sits in my garage collecting dust.

At this point I think getting an accurate compression test should be your priority. I should have mentioned the importance of this much earlier, but it slipped my mind :dizzy:. If you have good compression, good spark, air & gas in each cylinder, then it will run correctly. So which ingredient(s) are missing in #3 & #4? Tim

[freeb]

So I got a gauge that worked... Man, I wasted a lot of time with the bad one.:dizzy:

Here are my readings: #1 125psi. #2 130psi. #3 135psi. #4 145psi.

Since the 2 cylinders which aren't firing are #3 and 4, I should be able to rule out any compression related issues I think.

My TPS tested okay according to the manuals specs. I have tried clearing the ECU by disconnecting the battery and I still am getting code 51. Could this be the ECU itself:cnfsd: I would test the ECU but I broke my multimeter last time I tried. Just got a new one but a little hesitant to break another.

Thanks again for the compression testing 101 video, Tim. I should mention that the # 3 and 4 plugs aren't very wet at all after idling. (Maybe just a drop of fuel). However, if I actually take the van for a drive they will be wet.

I've gotta ask what the cold start injector does and if it could have anything to do with the issue?

[timsrv]

That's not the greatest results on a compression test, but I agree this isn't your immediate problem. If you reset codes by disconnecting the battery, you will need to leave it disconnected for at least 30 seconds, then to be sure it's not storing a new code, re-check before starting the engine.

These ECUs rarely fail, but they can and do. Based on everything else you've either checked or changed, I'm starting to think it could be an ECU or maybe the igniter. Get used stuff at the salvage yard or maybe off of eBay. Tim

[freeb]

Just discovered something. My van is a California Van. I'm trying to decide if I want to lay down the $90 for an ECU off Ebay yet. May look for an igniter at the junk yard tomorrow.

Just don't get why the plugs aren't really wet until its driven. Could it be the injector's after all? Why would the 2 cylinders be completely dead? Why did it start with only 1 being dead? Sorry, just thinking and typing. I need to get this van back on the road.

I'm wondering if there would be any other differences besides the ECU in a Cali van? Vacuum lines or anything? I just want to be sure the mechanic that did some work on it didn't overlook something since it was the emissions issue he was working on.

[timsrv]

I could be wrong here, but I don't think there is any difference between CA vans and those sold in the other 49 states. As for getting your van on the road, something is certainly missing here, but At this point I have absolutely no clue what it is. FYI, without hands on, the only things anybody can offer you is going to be speculation and guesses :dizzy:. Sorry this hasn't been enough for you. I'm sure you will find the the problem soon, and when you do, please report back with your findings and the solution. Tim

[llamavan]

I know the ECUs for California vans are different starting in 1986. Word of mouth is that the differences are strictly to do with the emissions system, but I've not had occasion to stumble on the specifics yet (only have one CA van that I work on ... so far).

Looking back to your very first post, you mention "an odd elec. type smell the morning it started misfiring" ... so testing the ECU (just to rule that out) and then inspecting and testing the wiring, particularly between ECU and the injectors (starting with anything that looks weird, and especially anything that sits next to hot engine parts) might be a good next step. Or vice-versa, since the code 51 is pre-existing and, as Tim mentioned earlier, it's really rare for an ECU to go bad (much more common for people to blame them). I worry enough about accidentally mangling 20+ year-old wiring myself; I shudder to think what a non-van-familiar mechanic might do. :dizzy: Flaky (damaged) wiring to the injectors would have a similar effect as bad injectors. I've also known people to mistake a really toasted TPS for "needs injector work", and you are getting that code 51.

Before you remove the intake manifold, order in the appropriate gasket(s) for as far as you think you might be going in. Toyota P/N 17176-73011 (the gasket between the two halves of the intake manifold) would be a must-have; a gasket for the EGR valve (Toyota P/N 25627-31020) might be good to have on hand since you mentioned a hissing sound (not normal on my vans). Also some vacuum hose; if you don't use it now, you will eventually.

Gwen

[Harbilly]

I'm interested in that gas smell after stopping. Not only do injector connectors fail but the things start leaking too. I was able to slide under the van and confirm a leaky injector after stopping the engine before I ripped it all apart. All my cylinders were still running, though, despite the leak.
I think vans that sit have more issues than vans that run - I know I have one of each.

[freeb]

Thanks for the help so far. Anything anybody throws out there is really appreciated. I'm learning hands on a lot of the basics with my Van and then some. So on one hand I'm enjoying the diagnosis but of course on the other its frustrating as #$*%!

I ordered an ECU off ebay. I dunno, just need to rule that out. Wishful thinking I guess. I did the resistance test at the ECU wire connectors according to the manual and got negative ohm readings. I honestly don't know if that points toward a problem with the ECU or something else but I guess I'll find out.

If that doesn't correct the problem I'll be pulling off the upper intake to check the injectors. Thanks for gasket references llamavan. I haven't been able to locate any fuel leaks but it may be worth taking another look at that. One thing that has been on my mind is the possibility that the injector wires got fried when I came close to overheating.

I'll let you all know what I find.

[freeb]

Some Updates:

Plugged in the ECU I bought off Ebay. No change. Finally pulled the upper half of the intake plenum off. I'm not really positive what I want to do next.

The first thing I noticed right away was a reddish brown color that dripped from the gas line when I disconnected it from the injector rail. I'm assuming it was rust. Probably not good.

Next thing was that the short and thin rubber hose that attaches to a fitting on the bottom right (firewall side) of the injector rail was not connected. I see that one end attaches to a thin metal line which loops around to the other side of the engine block and a rubber hose feeds into something with a red wire connection near the oil filter. I don't know what this is. Does anybody know?? Hope I'm not being to vague.

The EGR Valve had a really old gasket. May have been the reason I heard a vacuum leak in that area. Haven't been able to disconnect it from its pipe yet. Sprayed with some PB Blaster

The intake runners for #1 and #2 cylinders is really carbon and gunked up.

3 of the nuts for the chamber were loose!!

Does anybody know how the fuel delivery system works as far as getting the fuel to the injectors? Is it possible that it's not actually the injectors which are clogged? Could the fuel not be even making it to the #3 and 4 injectors for some reason?

The injectors wiring look okay. Didn't look like I have any leakage at the injectors. There was a lot of gunk around there and it seems that it would have been at least partially dissolved if they're leaking.

Time to tend to some bloody knuckles......

[llamavan]

Without even seeing it, I'm 99.999999% positive it's a vacuum hose. You'd have to have no sense of smell or vision to miss a gas or coolant leak, and those are the only other things that run around inside rubber hoses. So that's probably the source of your hissing noise. It could also be the source of the burning smell if it ended up resting on something hot.

There's a vacuum diagram pasted on the floor pan, driver's side (lift the seat to find it), but it's more of a reminder for those who already know what things look like. If you post a photo of the other end and the dangling end, I might be able to figure out where it's supposed to go (but hopefully someone else with hands-on experience will jump in — I'd just be deducing from diagrams).

I'm going to let someone with hands-on knowledge answer the fuel delivery (direction) question (and I hope someone does, so I can learn, too).

Sounds like taking the top of the air chamber off was the right move since you're finding lots of stuff that needs to be addressed. :dizzy:

Gwen

[timsrv]

That short rubber hose is most likely the vacuum line for the FPR (Fuel Pressure Regulator). Not having it hooked up would do 2 things: 1. Create a vacuum leak. & 2. Increase your fuel pressure. Since you have the manifold off, now would be a very good time to replace your FPR. These fail and are a PITA to replace with the manifold on, so now is a very good time to replace (consider it preventive maintenance).

The vacuum leak part of having that line disconnected is not good, but wouldn't create a problem to the degree you are having (you might not even notice). The increased fuel pressure is actually good (would make your van more resistant to vapor lock or "hot soak" issues). The "gunk" in these two runners, along with the wet plugs you reported earlier suggests you may have a blow-by issue (bad piston rings) or perhaps a leaking cold start injector. At any rate, since you have it mostly apart, take all the injectors into a shop to have them ultrasonically cleaned and tested. If there is a problem with any of them they will be able to tell you. I'm not sure what this costs in your area, but last time I had it done it cost me about $50. You will also need to replace all the rubber o-rings and rubber insulators that are used to mount each and every injector. Note: make sure that all the old parts are removed from your injectors AND the manifold before re-assembly (one sure way to screw things up is to re-assemble with both an old and a new o-ring or insulator stuck in there).

To find a place that can clean and check your injectors, just call your local Toyota service center and ask them where they take their injectors to have this done. There's usually at least one or 2 places that do this in every major city, and any reputable shop will know who it is.

Also, before you put the manifold back together, make sure to get it clean. Carbon and "gunk" in this area create problems. Make sure the big vacuum ports are clear of debris and gunk as well. If you can't get it clean, an automotive machine shop should have a washing machine that would do a nice job. Just call one and ask how much $$$. Good luck. Tim

[trestlehed]

Some Updates:
The first thing I noticed right away was a reddish brown color that dripped from the gas line when I disconnected it from the injector rail. I'm assuming it was rust. Probably not good.

You might have a rusted out gas tank. Back in the early '90's I bought a 1977 Toyota Chinook pop-top camper. It ran rough/power loss/stalling. I had the carb rebuilt as well as replacing everything such as wires, plugs, distributor, cap & rotor, etc.

I finally took it to a reputable independent Toyota mechanic who immediately found that my gas tank was full of rust and gunk. When I bought my 86 van, that was one of the first things I had checked out.

Remember how old these vans are... Original gas tanks 25 years old or so.

[freeb]

thanks for the replies. I agree that I probably had numerous vacuum leaks.:LOL2: Numerous.
I am bringing the injectors to be cleaned at Napa tomorrow. I'll be getting new O-rings also.
I think my EGR valve is still good. Diaphragm still moves up and down.
I'm a little uncomfortable going too crazy cleaning the inside of the intake chamber. Seems like if a bristle from a wire brush were left inside, I'd have problems.

The gas line that the reddish brown gas came from was the line that leads to the cold start injector. Wonder if rusty gas is left in this line still. Starts up easily when cold so the cold start injector should be good??

Hey trestlehead, I'm not sure what to do about this issue with the possibility of a rusty tank. I read that gas can also become gel like over time. I don't know why I didn't take the time to drain the tank. :swear: The old gas would be thru it by now but I'm not sure what to do about the tank itself now.

Just found out that the pictures I took of all my hoses prior to disassembly were lost from camera's memory. Fun.

[Sean]

I can't reccomend enough just taking in parts to a machine shop with a washer.... In doing my project I spent countless hours cleaning when I could have been more productive by taking them into the machine shop. The guy charged me about 20 bucks for a load of stuff and it got everything neat and clean. Well worth it to me.

you should definitely look into it and at least find out if it's worth it for you.

Sean

[skyflyer9]

I'd have to agree on taking the manifold to a shop to be run through the cleaner...

I must have spent four hours with brushes, rags, carb-cleaner, etc. trying to get my intake manifold clean. It was a complete mess, and you can't really get into the inner chambers all that well.

I finally took it in to a local shop, picked it up the next morning, and it was like night and day - what a difference!

Granted, my intake manifold was VERY dirty (340K miles on it at that point), but I should have just taken it to the shop in the first place...

[freeb]

I hadn't actually removed the fuel rail and injectors yet. Did that today. Caked in rust in the end of the 2 dead cylinder's injectors. A fine powder of rust came pouring out of the rail like an hour glass. :doh:

Had the 4 injectors cleaned and some o-rings etc. replaced for $135 at Napa. One injector tested 10 cc. over spec. They said it would still work but I wanted to see if anybody had any thoughts on that.

I'm gonna look into the intake manifold cleaning. How does it get so gummed up???

[timsrv]

Considering the PITA it is to remove these, I wouldn't install one that tests out of spec. If you're on a budget, get one at a salvage yard and have that one cleaned and tested. Re-assemble only after you have 4 confirmed good ones.

If the gunk inside your manifold has a trail that leads to the PCV and valve cover vent ports, then it's due to crank-case ventilation and can be normal. Intake manifolds eventually get fouled up inside due to the PCV (Positive Crankcase Ventilation) and the valve cover vent hose. These 2 larger intake ports suck the oily vapor out of the top your valve cover and recycle it back into the combustion areas. This is good because it helps prevent the formation of sludge and condensation inside the engine. It also keeps the interior of the engine at a slight negative pressure which helps inhibit external oil leaks (reduces the outward pressures on the gaskets and seals). The down side to oily vapor moving through your intake manifold is a gradual build up of oily residue inside. This build-up is very gradual but steady. Another negative aspect to crank case ventilation is over time this build-up problem becomes accelerated (due to normal engine wear). As the piston rings wear they slowly allow more and more combustion pressure/gasses to escape down and around the piston and into the crank case. The combined combustion leaks from multiple cylinders can eventually match or overcome the CFM (Cubic Feet per Minute) of vapor these vent ports can move.........and that creates a positive pressure inside the engine.

Now instead of these vent ports sucking in small amounts of vapor, they become overwhelmed by positive pressure force feeding combustion gasses into them (for a 2nd trip through the engine along with the additional vaporized oil that was picked up along the way).

One of the things you can do to check for blow-by is remove the PCV valve from the valve cover while the engine is running (leave the valve hooked up to the vacuum hose). If you can see and feel vapor puffing out of the valve cover, then you have a blow-by issue. This can be a good indication that it's time for a rebuild or at least a new set of rings.

If the residue trail inside the manifold goes back to the cold start injector, then it's possible this injector has been leaking and the build up is a result of that. Tim

[freeb]

Thanks for that info Tim. My manifold is a bit worse in the first two runners but all four are actually pretty black and gummed up. I will try the PCV valve test once reassembled. I think I remember doing that and getting getting the air coming out. The fuel line to my cold start injector had rusty gas in it so I suppose I should check the injector also.

I can't seem to get the bolt that holds the banjo fitting for the fuel line on the bottom of the fuel filter loose. I can't get a wrench around the part on the filter that would allow you to hold it in place while turning the bolt. Am I missing something or am I just not using the right tool? :cnfsd:

[timsrv]

Yeah, that one is always a PITA. At least that bottom line is flexible, so it can moved to a better spot. Take the top line off 1st, then take the mount bracket off the block. Now you can maneuver it around to a better spot and use a back-up wrench. Just be sure to use a socket or a box end on the banjo bolt so you don't bugger it up. Don't ask me why they made that job so unnecessarily difficult. Tim

[freeb]

Glad it wasn't just me in thinking that bottom line on the filter was a PITA. Now that I got the it removed I'm trying to figure out what the best approach to the rust in my tank would be. I did drain it and it was rusty and had some sediment. I think that the injectors clogged when it ran down close to empty on the fuel gauge.

[NEC]

I used to clean my old VW tanks with some water, a heavy chain and some Tide with bleach. I would remove and drain the tank, throw in a section of heavy chain, some water and some laundry soap. Shake it all around for a while, drain, rinse, repeat. This worked well for my old rusty steel tanks on the vws.

[freeb]

Thanks for that idea NEC. I've come across stuff on the internet recommending muriadic acid. I'd like not to have to dump a bunch of acid into the ground though. :no:
Just dropped the gas tank and I have a couple of pictures.
The first is inside the tank. There is a partition built in where the fuel pump goes. Entire tank is rusted but no leaks.
http://i56.tinypic.com/zl91yx.jpg


This picture is the fuel pump attached to its very rusted bracket. The fuel sender gauge is also in the picture. I think that's what it is anyway.
http://i51.tinypic.com/2442mpu.jpg

I'm not really sure where I should be starting now. I probably can't afford a new tank at this point. Fuel pump and gauge were working. Is it possible to just clean them? I'm thinking that anything at a salvage yard is going to be in the same condition. Appreciate any ideas.
ben

[timsrv]

I've had several van tanks apart and yours is the worst I've seen. I would suspect a salvage yard tank would look nicer than that inside, but who knows. If you can find one in a salvage yard (keep in mind 2wds and 4wds have different tanks), you could always look inside before purchasing.

Since everything was working, you could always clean per NEC's directions and put it back in. FWIW, your tank is rusty because that van sat around with an empty tank. Tanks that get filled regularly don't get rusty like that. Tim

PS: I have a good one I'd sell you for $40 complete with fuel pump. I already have the tank removed and sitting inside the van (I pulled it out of an 89 LE 4wd just like yours). Tim

[freeb]

My van's running strong again! Thanks Tim for the tank, pump and sender. Gauge is working fine. That was a cool trick. Had a couple incidents with fuel lines not being tightened enough and a coolant hose leaking at first start up. The coolant leak had me thinking I had a blown head gasket at first. Just sorta figured that would be next. Only needed to adjust a hose clamp position and leaking issue solved. :)>: Only issue I have now is the gas odor seeping into my house every time I open the door to my garage.:dizzy:

Next up is the obnoxious whine from the power steering pump. Hoping that cleaning the screen in the reservoir will fix it. Its leaking as well and the power steering is pretty intermittent.
ben

[timsrv]

Awesome! That's great your persistance paid off :). Sorry we didn't get this figured out sooner, but at this point in your van's life all that other stuff you did was probably needed anyhow. At least now you can drive with confidence AND you have some spare parts :)>:.

Yotamog came over today and picked up the engine from that same van. The transmission from that van also went to save another. I'll be using the differentials out of it on my 5 speed to off-set the gear ratio change I'll get from big tires. I'm also going to put the starter from it in my fork-lift. Parting a van out isn't so bad when they help keep so many more vans (and fork-lift) on the road. Tim

[gushaman]

:dance2::clap::clap::thmbup::yes::drunk::drunk::dr unk: