Hello all hopefully someone can help me solve this problem, my car is running awful. Just had a swap from 305 to 350 zz4 motor and used the original TPI system except added high flow injectors and had a new corvette prom chip installed. Now the car surges at idle and had to bump the idle up to 1,000 RPM to
lessen the surge and ensure it won’t stall. The car will tour the parking lot on its own because the idle is so high and the surging is annoying to say the least. Also it sometimes bogs and hesitates when I hit the gas. I ordered another 1985 prom chip of eBay to see if that might help, but it won’t be here for a few weeks. Any help would be greatly appreciated, the car is not fun to drive.

Thanks

 

Two versions of hlh if that’s the bcc your using 3200 is the latest.
better to custom tune and datalog to refine the tune win aldl connects to the 870 ecm. Better to upgrade to the 165 ecm

 

Thanks! I have heard the 1985 Ecm is the worst but your suggestions should help.

 

1985 Corvettes had 24 lb injectors. What size did you install?

 

I installed 30 lb fuel injectors as hypertech indicated I needed for their chip. When calling them they indicated the chip is for a stock engine so any modifications may effect it. The replacement 350 zz4 only really has a modified cam vs the regular stock motors.