Hello everyone,

Hope you can help me solve an issue with a car I just purchased. 1991 Z28, 350 TPI. This car developed a rod knock, and then proceeded to sit for 3 years before I bought her. I Built up a new motor, all stock except for a ZZ4 cam, valvesprings, and decked heads. Engine was very rough when first fired, but after a couple vacuum leaks, a bunch of fuel system cleaner, a couple of injectors, and the car is pretty much driveable. In fact, it runs good when it's first fired until it gets hot, at which point it develops a lower RPM stumble and rough idle. Even when its running good I think it's missing some power

Is the ZZ4 cam radical enough that the computer is getting confused? or do I have other issues to sort out in terms of crusty old sensors? I'm willing to rule out most types of mechanical problems, as this car, at times, can really haul. It's just that most of the time I have some driveability issues.

Thanks for any help or suggestions you all can provide!

 

having the same prob right now with same engine,not the comp just had my engine pulled and had more work done