I Have a 1998 Z28 with about 40000 miles the car had been sitting in my garage for the past year. I took it out the other day and it ran fine, then I installed the hypertech tune on it and ever since I did that the car has been hesitating to start some0times but when it starts running it runs great. So I installed the factory tune back and the problem is still there, sometimes it starts right up and other times it takes a few minutes to start up. The only other thing I did to it was detail the motor. Any ony have a clue what my problem could be?

 

Since it was sitting for so long you might have a fuel issue. Is the car throwing any codes? I would get it scanned just in case.

 

Sounds like the injectors are getting clogged up and or the FPR is screwin up...probably injectors.