I wish I could shed more light on the rest of this, but I can tell you my A/C idle up, VSVs and wiring remain, and I do not get a CEL.Originally Posted by Bala
Gwen
I wish I could shed more light on the rest of this, but I can tell you my A/C idle up, VSVs and wiring remain, and I do not get a CEL.
Gwen
1985 5-speed window cargo van set up for llama haulin'; 345K ("Trustyvan")
1989 4WD 5-speed DLX; 410K and an odd sense of humor ("Skylervan")
Thanks for the input. It must mean that my TPS is just not accurately dialed in.Is the throttle stop screw supposed to be set at closed throttle position? I can't find much info on this. Or is the stop screw supposed to be a little further advanced (not fully closed)?
Okay, well here's an easy way to check for correct adjustment of your TPS.
Take your D/S seat belt reel off and unplug the ECU. Now take a couple of paper clips and put them in terminals marked IDL & E1 below:
Now take your multimeter, set it to emit a tone when continuity is detected and hook it up to the paper clips (it should start emitting a tone):
Now take a .57mm feeler gauge (.022") and place it in between the throttle stop and the adjuster screw:
After inserting the feeler gauge, the multimeter should still be emitting the tone. Now remove the feeler gauge and insert a .85mm (.034") feeler gauge into the same spot (you may need to stack 2 or more gauges together to obtain this thickness). If the tone stops with the larger feeler gauge(s) inserted, then your TPS is adjusted correctly and no further action is needed. If you get any different results, then your TPS is out of adjustment (or it's no good). Since yours is new, if there's a problem, it will most likely be an adjustment issue. To adjust, remove the throttle body, take a .71mm (.028") feeler gauge and put it between the throttle and the stop (as pictured above). Now loosen the mounting/adjustment screws of your TPS and slowly rotate the plastic body of the TPS until you find the spot where the tone on your multimeter is on the threshold of going on/off. Once you have found that spot, tighten the adjustment screws and re-check your TPS per the procedure above. While the throttle body is off, clean it out good with throttle body cleaner and compressed air. Use a new throttle body gasket Toyota part #22271-73011 when you put it back on. Also check the condition of the 8mm (5/16") coolant lines in this area and replace them too if they need it.
Note: To anybody with a used TPS, my advice is to not waste time with one if you don't know it's history. Bad TPS's are very very common so when in doubt just replace it. There are detailed tests outlined in the manual, and more often than not a used TPS will fail at least one of these tests.
CLICK HERE for more information on cleaning throttle body and replacing/adjusting TPS.
Tim, thanks a million! The book is confusing and calls for feeler gauge sizes that I can't even find. How do I make sure my throttle stop screw is properly adjusted? Doesn't that need to be proper before adjusting the TPS?
As a general rule you should never need to adjust the stop screw. Toyota sets them to stop the throttle about .095" away from the housing. If it's significantly different than that, then you should put it back to about .095", then start over with testing the TPS. If the TPS tests good, perhaps you can find the original spot of the stop screw by using the TPS adjustment procedure. If you change the stop screw position, and you cannot dial in the TPS, then you will need to pull the throttle body back off and set things up from scratch. Use the idle set screw under the rubber flap to re-adjust the idle speed. Tim
This site rules Tim! I thank everyone of you dedicated van owners. Engine Service Connecter actually works (when there's a light bulb in the dash that a hack job mechanic didn't take out), TPS dialed in to the T, ignition timing set...my van is cruisin! No trouble codes, no worries... Was wondering though...what with the AC would ignite code #51?
Glad to hear you successfully solved your problems! I'm not sure why you'd get a code from an AC issue, but I know there are 3 inputs to the ECU from the AC system: the AC idle-up VSV, the AC magnetic clutch, and the AC cut relay (all of these talk to the ECU). Since the AC switch and the AC amplifier are also tied into these components, a short or malfunction in one of these could possibly throw a code??? I think this is why the FSM says to turn off AC and all accessories before jumping the Check Engine Connector. I'm merely speculating because I've never traced a code 51 back to an AC component. Although it may be possible for one of these things to throw a code 51, in my experience it's never happened (at least not to me). Every time I've seen this code it's always ended up being a TPS issue (no idle signal from the TPS). Tim
I'm not getting any error codes coming up. Can you fill me in on how to check the ECU for stored error codes?
I thought it kept some kind of record of the history of error codes. I guess it just keeps the latest? To reset everything you just turn the key to the off position then it gets reset?
The ECU stores codes until the battery get's disconnected or the EFI fuse gets pulled out. Doing either for 30 seconds or so will clear the codes. Clearing codes should be done each time a problem is repaired. If you don't clear codes they will remain stored in the ECU. This can be confusing the next time you check codes as there could be multiple codes built up from previous problems that no longer exist. Tim
Hello,
I have never changed my TPS and have had my automatic 4WD Van from 90k miles to now 207k miles. It is shifting rough when cold, revving a lot before kicking into gear when trying to reverse and then spinning out a bit. Once it gets to running temp it seems to handle a little better. Does this sound like the symptoms of a failing TPS? I did a tune up 2 years ago, new muffler 2 years ago, replaced O2 sensor 3 years ago, and exhaust is still a little stinky but not smokey. Trying to get a confident diagnosis before I start replacing parts.
Thanks for the help!
Peter
What (if any) codes are you displaying?
There is no check engine light on, could it still be sending a code?
Yes. For more information, click on the link in post #29 of this thread (above). Tim
Got codes 22 and 51. Am I still looking at TPS replacement or maybe something else?
Thanks Tim!
With those codes we must be talking about an 88 - 89 van......right? Code 22 is an ECU Temp Sensor code, but if that sensor is bad the van will run REALLY bad, so I'm guessing that's an old code that wasn't cleared. Code #51 is almost always a bad TPS. I would recommend clearing codes, driving the van around for a day or so, then check codes again. If code 51 comes back I'd replace the TPS. Based on my experience with these vans, if the TPS has more than 100k miles on it or if it has an unknown history, I'd probably just go ahead and replace it. Keep in mind there's an adjustment procedure, so familiarize yourself with that before you do the job. I posted a video of how that's done at the end of the 1st post in THIS THREAD. Tim
Hi Tim,
Replaced the TMS, got it properly adjusted by following your video (had to use a VPN to view it on YouTube, not throwing codes anymore, but still having the same issue of rough shifting when it isn't warmed up yet. Most obvious example is having to rev the engine in reverse and not feeling it engage in gear until I hit higher rpms, so it spins burns out a tiny bit. Could this be as simple as an overdo transmission fluid change? Anything else I should be investigating? Is there a torque converter that receives fluid from the transmission?
Thanks for your generous time and wisdom!
Peter
Have you checked transmission fluid level? Not shifting into gear @ low RPM while cold is the classic indicator you're running low on ATF. Tim
Unless I misread the dipstick the level looked a little over max actually.
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