[Mope]

Hi,
My buddy has a 92 chevy pickup, and when he pulls up to a stop light after the engine is at operation temps, the idle will drop really low, and the truck shudders like it want to die, but then jumps back up again. It only does it at idle speed. It is a 5 speed with the 350. We have cleaned the IAC, new plugs cap rotor wires etc. but still no luck. Does anyone have any ideas? Ya I know, its a chevy and thats probably it

 

[xceed55]

The Throttle Position Sensor,, My guess anyways. I used to have a GMC with the same problem. The problem went away after I replaced it and checked for vacuum leaks at the intake. (Spray carb cleaner around the intake and throttle body gaskets while it is idling, if the idle drops you have found a leak.)

 

[98QuadCabV10]

I agree with xceed55. My car did the same thing every time I put the clutch in, it wanted to die. I replaced the TPS and never had a problem since then. Scan it for codes. If you need me to I could find which wires you need to jump to flash codes.

 

[eazyasone23]

hmm i wonder what that could be, i noticed something similar to that on my truck. i think i might have a clog something.

 

[Mope]

I sure appreciate the input. Could you tell me what wires to cross to get the codes?
Thanks again.

 

[98QuadCabV10]

Jump terminals A and B with a jumper wire on the ALDL conector. I'll try to get a pic posted.

 

[98QuadCabV10]

Turn key on (engine off) jump the a and b terminals and the check engine light should flash. If you get a code 12 that means everything is operating normaly no codes.

 

[Mope]

Great!! Thanks for the reply, We'll see what happens. BTW where is the TPS on this truck. And do you know about what one will cost? Thanks again.

 

[Dodgevanman]

The TPS is going to be located on the throttle body. Cost varies from make and model and by parts store.