1992 305 TPI engine runs great except when I stop at a stop sign it dies, it cranks right back up when I mash the throttle open a little bit I have changed the throttle sensor it does not help. Sometimes I drive the car 3 or 4days without the problem then it acts up and after being cut off for a couple of hours you crank it up and there is no problem for another several days. Any suggestions.
Thanks

 

I can't say this is related to your problem, but I had a 6 cylinder Grand Prix that would do that after driving it in wet weather. I always thought it was a sensor or wiring that was the problem. Dealt w/ it for months. The problem was finally solved by adjusting the minimum idle air - the typical screw stop for the throttle.

The procedure I used was to warm the engine up to normal operating temp. Then I made certain the IAC control was completely closed - you'll find the procedure on this site for 3rd Gen cars - and disconnected it. Now the minimum idle adjustment screw is the only thing controlling the idle - it was really low. I had to knock out the factory plug to access the screw, which was a torx head. With the engine idling, I adjusted the screw to bring the idle up to spec and reconnected the IAC.

Now, the IAC increases the idle to compensate for A/C or anything else that puts a load on the engine (trans in drive, electrical accessories, etc.) like it should. But, the minimum idle screw never lets it get so low that it stalls.

Haven't had the problem since.

 

Thanks for the suggestion I have been working on carb. cars just so happened I had bought another car and I decided to change the IAC sensor before I adjusted it and that was the problem.

 

Great to hear and glad to help.

Just so you have a better understanding, the IAC is actually a control - it doesn't measure anything like a sensor does (ex: throttle position. coolant temp, air temp, oxygen, etc.). It operates, or in this case, moves based on a signal from the ECU to control the idle speed.