Multiple bad TPS replacements

[Blamalam]

I'm (slowly) working my way through a very poor idle situation with my '94 4R with the 3vze, and when I tested the TPS per the FSM it failed. Okay, no problem. I'll just get a replacement, right?

The first replacement was a Beck/Arnley from RockAuto. No matter where I put the sensor, I couldn't get the idle reading below 2.3k ohms. It wanted to hover around 5.86 or so, or infinity.

The second replacement came from ToyotaPartsDeal, an OEM Denso unit. It too failed, with the idle reading somewhere in the 4.88 range.

The third replacement was another Beck/Arnley, this time from Advance Auto. Failed same as the first two and in the same range for IDL-E2.

I've gone over my throttle body with a fine-toothed comb looking for interference between the throttle stop screw and arm, and I've adjusted the stop screws (opener, throttle stop, and dashpoint) to where they no longer make contact with the relevant arms. I've cleaned the throttle body butterfly plate and the throat, both of which are now spotless.

Is it possible that I got three bad sensors in a row?

 

[Ahlem]

Maybe you have a bad meter or operator error. Get a friend with a different meter to test the parts and see if the results are the same.

 

[penbergm]

If your throttle body is not adjusted correctly, you will never get the tps adusted.
The throttle stop screw needs to be adjusted so the flap in the body is just barely off fully closed. This is not the idle adjust screw or the throttle cable linkage adjustment.

 

[flyinhawaiian01]

Its also much easier to just pull the throttle body off and do the setup on a workbench while its sitting in a vice.

You can then snug the screws up then just tap it lightly with a screwdriver handle. Finesse is the key here! I'm not talkin' about a flatblade screwdriver you could use for a prybar! More like a #1 philips!!!

And, if you have a good metric bolt supplier in your area, I'd suggest changing the philips screws out for allen bolts, they're much easier to use with the tps.

Throttle plate should be set as follows:

a> Loosen locknut of the throttle stop screw, loosen the stop screw until it is about to touch the lever.

b> Have throttle stop screw touch the lever, then screw it in ¼ turn and lock it with the locknut.

c> After installation of throttle body, make sure that engine rpm does not change even if vacuum advance port hose is pinched.

You're using a 0.47mm/0.0185 in. feeler gauge at the throttle stop screw, right?

I've done this setting so many times in the past on at least 10 22RE/5MGE engines, I can actually set it by listening to the idle with the feeler gauge! No meter needed!!!

 

[Blamalam]

Its also much easier to just pull the throttle body off and do the setup on a workbench while its sitting in a vice.

You can then snug the screws up then just tap it lightly with a screwdriver handle. Finesse is the key here! I'm not talkin' about a flatblade screwdriver you could use for a prybar! More like a #1 philips!!!

And, if you have a good metric bolt supplier in your area, I'd suggest changing the philips screws out for allen bolts, they're much easier to use with the tps.

Throttle plate should be set as follows:

a> Loosen locknut of the throttle stop screw, loosen the stop screw until it is about to touch the lever.

b> Have throttle stop screw touch the lever, then screw it in ¼ turn and lock it with the locknut.

c> After installation of throttle body, make sure that engine rpm does not change even if vacuum advance port hose is pinched.

You're using a 0.47mm/0.0185 in. feeler gauge at the throttle stop screw, right?

I've done this setting so many times in the past on at least 10 22RE/5MGE engines, I can actually set it by listening to the idle with the feeler gauge! No meter needed!!!

I'm working with the throttle body on my coffee table so that I can more easily get to the TPS to adjust it. I'm using a .020" shim per the FSM between the throttle stop screw and swing arm.

At this point I'm leaning towards my meter being wonky. I use it every day for work (I'm a 3D printer tech) and haven't had any issues, but I'm going to try to borrow a different meter and see what the IDL-E2 reading comes up as. If that fails, I'm just going to throw the Denso back on and try to adjust by ear.

Thanks for the help, guys!

 

[flyinhawaiian01]

Ahh! Didn't read your initial post very well! You have a 3vze, the settings I posted are for a 22RE, although that would be really close either way.

For tuning by ear, I use my feeler gauge and just turn the tps until the idle changes. Its right at that point where the idle drops/raises, that's where you want it to be sitting, right when it drops.

Good luck and post back! Would love to know if that works for ya! I know the MAF sensors from Rockauto have serious issues too, and the last Denso o2 sensor I got from them was bad also.

 

[Blamalam]

After reading everyone's responses, I started to wonder whether my meter might be at fault, so I checked it today against a 10k resistor. It measured 9.85k, so it's dead-on as far as the published specs go. I can't figure out what's going on.

I have all the stop screws backed out completely--none of them are touching their associated swing arms. Also, the TB butterfly valve is snugged up against the ridge in the throttle body float, so I can pretty much rule out mechanical interference. The only thing left is the sensors, right?

 

[KidVermicious]

After reading everyone's responses, I started to wonder whether my meter might be at fault, so I checked it today against a 10k resistor. It measured 9.85k, so it's dead-on as far as the published specs go. I can't figure out what's going on.

I have all the stop screws backed out completely--none of them are touching their associated swing arms. Also, the TB butterfly valve is snugged up against the ridge in the throttle body float, so I can pretty much rule out mechanical interference. The only thing left is the sensors, right?

Three DOA sensors in a row seems super fukky, but I guess stranger things have happened. I would try another meter just to be safe, a $5 Harbor Freight cheapo will tell you what you wanna know.