Throttle Position Sensor

[sxpear2]

My 91 turbo wants to die when I quickly let off the throttle. It also has an intermitant miss. I've swapped the air fuel meter with a know good one and still have the problem.... Is this a symptom of a defective TPS? oh, yeah, I've replaced plugs and wires....

[bgrieger]

Could be out of adjustment, or it is the dashpot under the linkage on the TB. Dashpots slow the final closing of the throttle plate, and help avoid starving the engine for air on quick throttle release. Basically gives the ISC time to compensate before finally closing.

As for the miss, plugs, wires, coils, ignitor, fuel injector, etc, etc. These are a bigger bitch to find.

[OneWingedAngel]

You can test the TPS using the instructions found here:
http://www.cygnusx1.net/supra/librar...fi/FI_101.html

Also check for boost leaks. Are you still boosting your normal amount? You might also try cleaning the ISC.

[cdnsupra]

quickly dies when you let off? do you have a blow off valve venting to atmosphere?

you could also have an air leak in your piping system.

a worn spring on the tps can also cause weird idling problems.