my car is a 5.0 TPI, '91Z28, the car won't idle when it's cold, and when the engines up to temp, it runs really rich, very rich. I bought a new idle air control module but haven't had the time to put it one yet, does any one know what this sounds like?

 

Maybe a dead 02 sensor?


Or a broken FPR ?

 

O2 sensor is not in the loop when cold. First, check for vacuum leak or loose hose to MAP sensor. Then check CTS sensor. Next problem areas, fuel pressure and leaking injectors.