I am currently fighting with a co-worker's 95 Camry 2.2 that likes to die once warm, and has a host of other running issues. I have been correcting previous "repairs", including the timing belt being off two teeth, and the ignition timing being way off, now I think the throttle has been messed with. Unplugging the TPS had no effect on the way it ran before, so the TPS was replaced and I cannot get it into the range specified by Haynes at the stop screw. Of course Haynes says "take it to a dealership" so I'm kinda stuck on that. Well within my skill range with the measurements to work with-

 

To adjust:

Disconnect electrical plug from TPS.
Loosen 2 screws that attach TPS to throttle body.
Apply vacuum to throttle opener dash pot or use other means to retract the dash pot plunger.
Insert 0.024 inch shim between throttle stop and set screw.

Connect ohm meter between IDL and E2 electrical terminals of TPS.
If the TPS is bolted to body, these are the two bottom terminals.

Rotate the TPS CW until the ohm meter indicates continuity and tighten screws.

Continuity is either yes or no.

To check results:

Insert 0.020 thick shim as above. Terminals should have continuity.
Insert 0.028 thick shim. Terminals should have no continuity.

 

Thank you for replying, but what I need is how to set the throttle itself, then I can set the TPS. The throttle has been messed with, the screw had about 1/4" of threads exposed that were obviously not exposed as long as the rest of the screw. I put the screw back to where it looked to have belonged, and have set the TPS, but the ignition timing needs to be at about 20* (with jumper in place) for the car to run at all.
I spent the better part of this morning talking with two different dealerships, the first just gave me blank stares and wanted to put it on a scanner, the second offered advice about setting the RPMs to 950, assuming the TPS was correctly oriented. The second tech also said that Toyota stopped giving the procedure for adjusting the throttle, they want you to buy a new one all nice and calibrated from the factory, but I am not going to spend that kind of money to fix an adjustment. He said they stopped giving this info in the mid 90s.
Working on Fords, there was a procedure to set the throttle blade position on the early 4.0, and it would act just like this car if someone messed with the setting. The procedure was something like: place a .005-.010 feeler gauge at the bottom of the throttle bore, and close the throttle on it. Adjust the stop screw to have a slight drag when pulling the feeler gauge out.
Is there a procedure for this for the Toyotas? Maybe someone has a set of manuals from the 90s that has this?

 

No procedures found in Camry service manuals going back to 1990.

A check of a 95 4-cylinder found the screw extending out about 3 full threads not including whatever partial thread was at the tapered end of the screw.

After setting the screw retract dash pot plunger so clearance is 0 inch between screw and throttle. Ohm reading between VTA and E2 terminals should be 0.2-5.7K ohms.

With TPS bolted to body VTA is 2nd terminal from top, E2 is bottom.

With engine warm, trans in neutral, all acc and cooling fans off, rev engine to 2500 RPM for 90 seconds and release. Idle should be 750 +/- 50.

Jumping the terminals for timing drives IAC valve closed. Idle RPM should now be effected by the stop screw.

Perhaps Toyota listed a procedure for setting the screw in a manual for another model of car. Try a search of past posts at the Toyotanation website.

The screw adjustment procedure may also be called setting the curb idle.

 

I haven't been able to find anything on adjusting the throttle plate, just how to adjust idle speed via the bypass screw, which I can't find on this car. I adjusted the one on my old Hi-Lux, usually to get an unattended high idle for jump starting cars.
I found that the IAC was halfway unplugged, so it probably wasn't working. It's plugged in now and the idle is a bit more stable, but now it's acting like it's running out of fuel. I'm going to put a fuel filter on it today and hopefully that clears up this particular issue. The guy's wife is starting to make little comments about how I keep putting parts on the car and it's not fixed yet, I keep trying to tell her it has a lot of problems that need to be sorted out from the start so the car will actually be fixed. She's the sort of person that got me away from automotive work and into steelwork.

 

Well, I guessed at the throttle setting, putting it where it looked like the buildup line was originally. Set the TPS to that, and it ran decently until it warmed up, then it went right back to it's old tricks. I did a voltage test on the MAP sensor, it was just barely below spec with the key on engine off, so I left that. There was some buildup on the fitting the MAP and FPR vacuum line plugged into, so I cleaned that out. It ran a little better, but still died and shook at idle. After a few hours of staring at the thing, I ohmed the coil. It was slightly below spec, but a closer look showed some cracking on the plastic housing. I pulled it, and found the epoxy was cracked and there was evidence of arcing through the crack. A new coil, set the timing at 10*, and it runs like a new car. All this also fixed an odd shifting issue the car had before, where on downshift it would seem to just rev in neutral instead of actually accelerating. I'm guessing the MAP sensor fitting cleaning and TPS calibration took care of that.

 

Great job on getting the car running fine. Thanks for posting back with repairs.

As to your friends wife, tough to diagnose a car when so many things are wrong and someone fiddled with the adjustments. Return the car running like new then politely pass if asked in the future to do repairs.