TPS Set-up

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I have a '92 with 215,000 on the clock. For the last few months it has been acting like it is running lean in certain throttle positions; that is starting from a stop, applying some normal amount of throttle it stumbles alot and back-fires through the intake (pop-pop-pop). It is worse when the engine is cold.

After extensive research on this forum I changed the fuel filters, checked the plugs and wires and finally setlled on the TPS. I tested it according to the Chilton manual, which it failed. I bought a new one from Toyota, installed it to no avail. It runs the same or worse. I noticed that the sensor has a large amount of adjustment built into the mounting.

I was hoping someone here could explain the TPS Set-up for a 1992 3FE, or what else I should try.

Thanks.
 
For the tps adjustment there are 2 methods- feeler gauge and voltmeter. TSRM recommends the feeler gauge method.

Feeler gauge-

Pull the connector off the tps. Put a .93mm gauge between the throttle stop screw and lever on the throttle body. Loosen the 2 tps screws. Put your ohm meter between IDL and E2 and turn the tps until you get 0 ohms. Tighten the screws on the tps. Put in a 1.09mm gauge between the throttle stop screw and lever to make sure IDL to E2 is open. If not, the ecu will think the throttle is still closed during open throttle and it will just cycle rpms from 1600 to 2500.

Volt meter-

Connect volt meter to VTA and E2. Adjust until you have 0v-0.5v output. Make sure IDL to E2 is shorted when closed.

Also to note, If the IDL/E2 is open at closed throttle, it will throw a code 51.

As far as your problem, have you checked timing?

Ninja edit: Buy a Toyota manual and use the Chilton for a fire starter.
 
Thanks Poppy.

I have not checked the timing, so I will check. Which method is more accurate, the feeler guage or volt meter method.

Good thing winter is coming so I can use the Chilton manual for its appropriate use.
 
No problem!

The volt meter method will work, and is quicker/easier. Esp when you don't have feeler gauges.

The feeler gauge method is more accurate for sure tho.
 
I tried the feeler guage method. I could not get the Ohms to go to 0 in any positon. I tried the method that Cruiser Jimmy posted in 2007. Those numbers were within tolerance.

My timing light crapped out, so I will have to wait untill tomorrow to check the timing.
 
What method is that?

Touch your meter probes together to make sure they read 0.

If the meter is ok, sounds like you didn't get the tps installed correctly. If you miss the tabs or put it on the wrong side of the tabs it won't work.
 
The feeler guage method is the one I could not get to work. The meter I have is a good digital one. It is strange that the area where the throttle-stop screw rests moves (looks like it has bellows around it).

I checked the timing, it is right on.

I will try the TPS set up proceedure you listed, and I will try to clean the Fuel Pressure Relay.
 
I found the correct throttle stop. Got the TPS adjusted as you indicated. Still not running any better. Even in neutral/park giving it some gas will cause back-firing in the intake. It is at its worst when the engine has been running, but not fully warmed up, and trying to start from a stop. A lot of pop-pop-pop.

What do I do next?
 
not sure if your issue is resolved but came across this post searching for solutions to my problem

Sorry i dont have a link but I have read that you need to use an analog voltmeter to test the TPS.

Perhaps it will help and maybe someone will confirm this.
 
You can use an analog sure. But the tps is a static signal while adjusting so a digital is fine. Something that has a variable/fast signal such as a speed sensor or o2 sensor then yes, analog is the way to go.
 
For the tps adjustment there are 2 methods- feeler gauge and voltmeter. TSRM recommends the feeler gauge method.

Feeler gauge-

Pull the connector off the tps. Put a .93mm gauge between the throttle stop screw and lever on the throttle body. Loosen the 2 tps screws. Put your ohm meter between IDL and E2 and turn the tps until you get 0 ohms. Tighten the screws on the tps. Put in a 1.09mm gauge between the throttle stop screw and lever to make sure IDL to E2 is open. If not, the ecu will think the throttle is still closed during open throttle and it will just cycle rpms from 1600 to 2500.

Volt meter-

Connect volt meter to VTA and E2. Adjust until you have 0v-0.5v output. Make sure IDL to E2 is shorted when closed.

Also to note, If the IDL/E2 is open at closed throttle, it will throw a code 51.

As far as your problem, have you checked timing?

Ninja edit: Buy a Toyota manual and use the Chilton for a fire starter.
I realize this thread is very old, but I am trying to recalibrate the TPS on my 94 80 series.

In your description of the feeler gauge method, you don't mention using a vacuum. Everything else in that section seems to follow the FSM, except the use of a vacuum to pull out the throttle stop. Is that not necessary? I don't have a vacuum so I am trying to avoid running to the hardware store to rent one. And even if I had one, the FSM is pretty nondescript on where to apply the vacuum. Adjusting it the way you described seems much easier, but I don't want to skip using the vacuum if it is actually necessary.

Thanks for the help!
 

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