WheelmanZ28

This a little long one so I will apologize in advance, thank u for reading on...

All the problems started with my car when I had the Hot Cam Kit installed. Before it, the car ran excellent and the motor seemed very strong. (One of the reasons I bought the car in the first place) However, a few problems developed. 1st. The car developed this random miss that only occurred a few times, in which the car would shake ratther violently at low RPMs, and a lot of popping was occuring when i would floor it from low RPM.

When the Hot Cam kit was installed, The miss got worse. I replaced the coil and Opti along with plugs and wires and the problem seemed to be solved. However, my car only ran a 13.7 @101 MPH with 3.73s and all my other mods, and later a 13.9 @97 MPH when i dropped to a 3.42 gear and switched to PCMforless programming over my previous street tune.

So I checked over the entire car. Fuel pressure and volume - Fine. Valve Lash - Fine. Ignition - Fine. Programming - Fine. The one mistake I found was the my vacuum pressure was messed up. I replaced my stock lifters (which were later noticed to be shot) with some Comp Cam Pro Magnums. Now the car feels a little quicker, but i doubt it is at the level it SHOULD be at.

I have also noticed my low RPM miss has returned. It has only happened a handful of times. Usually when I am coasting at 45-55 MPH at about 1500 RPM. When I floor it from there, I occassionally hear a loud POP, and the car doesn't accelerate unless i let off the gas and hit it again.

So anyone that can lend some insight into my problem, I would greatly appreciate it. I have gone through so much time and effort and money to fix the car, and i see no results. I am beyond frusturated at this point. My car should be running mid to high 12s with my mods, not stock camaro times of very high 13s. Thanx for reading, and once again i appreciate the help.

WheelmanZ28

slopokrodrigez

An off idle stumble can many times be attributed to the EGR sticking. Clean it or replace it. If I were you and the car has a lot of miles, I would change the small inexpensive sensors like the MAP and the TPS. Have the injectors professionally cleaned. Clean the TB and the IAC. If you get a chance, check the IAC counts too.

WheelmanZ28

I had a basic scanning done of my car by my mechanic. Pretty much everything turned out OK accept for the Vacuum pressure, so I replaced the Lifters. The car seems a LITTLE better, but i don't think it is where it should be yet.

WheelmanZ28

TTT

HardcoreRM125

Is it possible that its not timed rite ? Or jumped time somehow? My old dirtbike jumped time once , was running fine , clink , and then it had no nuts , and would stall if it was under any kinda load at all and floored ... had to ease into the throttle and stuff ...

z28marine

do u have the Gm part number for the throttle body gasket? I want to clean out my IAC too, but need the gasket.