My car is a great car when it runs good. But when it doesnt run right, it'll make me lose races that I should have no problem. Before I get started I will say what I have done to the car so maybe it can pinpoint this problem. Its a 94 z28 lt1 w/ reworked heads, bored .30 over, racin lifters, lt4 intake manifold, ram air, mas flow sensor, holly throttle body, 3.73, bulletproof rebuilt tranny, hypertech stage 3 comp programmer.

Now to the problem. Say its running great and out of nowhere my service engine soon light comes on and my car shifts tremendously harder and at later RPMS, it shifts so hard it will churp the tires not even getting 1/4 throttle. It seems to give me alot more torque but when I get at higher RPMS the power is not there. And then after I deal with this sometimes the service engine soon light will go off and run just great like nothing ever happened. What I am confused about is my transmission (rebuilt right 4l60E) is electric shift and my programmer allows me to edit the shift points to my liking. Sometimes it shifts great, sometimes it doesnt want to shift. So this makes me think my programmer is maybe messing with my ecu on my car, or my ecu is going bad. I hope for no one to have this problem, but it would be nice to figure out what the heck the deal is. Camaro's are known for consistency, but mine is like the black sheep. If anyone has any ideas or has had this problem keep me posted.

Thanks,
Kyle

 

so you didn't have the computer tuned at all besides with the HPP3? i hope you meant you have lt4 heads...cause otherwise your heads and manifold won't fit together. i see no mention of a cam either...

but if all you have is the hpp3, then i'd get a full dyno tune on the car. hypertech isn't going to give you a good tune for the kind of work you're talking about your car having. i also see no mention of headers or exhaust...might want to get those as well

 

X2 on what Whammer said. Your motor is telling your computer somthing it's not used to hearing and not jivin! Get a tune quick!