I have this 94 Z28 with the LT1 motor. It starts up fine and runs good for about 30 minutes or until the motor gets warm. Aftewr that it rapidly misfires and loses all power. It gets to the point of cutting off. I have changed the IGM Module, Coil, and Plugs. I took it to a mechanic and he told me replace the distributor, module and distributor cap. It seems like that is alot to do when I figure that if it runs good for alittle while it should not be the distributor or the cap, cause they run off the crank. Does anyone have a clue or have they had this problem? ALso does anyone know if the 94 models had a crank placement sensor? The chevy place told me no, but I sometimes don't think they know how to put gas in a car. Also, is there any way of it being something easier than the distributor?

 

Any MAL indicators? Check engine light.

 

Sounds like the Opti Spark is going bad (it's bascily the distributor,cap and rotor).

 

first off, the distributer runs off of the cam. but anyways. it might be a sensor or a few that are causing the ecm to get incorect readings. you could try using a scan tool, or you could just bite the bullet and get a new distributer and cap. take it to a good shop and see what they say.

 

1200 dollars later, it was the opti-spark. Found out some things though, if anyone else has this problem to look for the coil and IGM module cause both had a factor in the opti-spark going bad.