Before the tune i just got a 383 with the lt4 conversion with the hotcam, it ran but once warmed up i would have to break and gas it to keep the rpms up? but i drove it about 15 miles total on the new engine.

 

That doesn't sound right. I'd think even with a stock tune it should of run better than that, but i've never tried a stock tune on my H&C car.

 

maybe fpr or fp then?

 

It sounds like the VATS system to me. I have a project car that didn't have the vats disabled and it would run for 3-5 seconds and shut off. I could keep it running by squirting starting fluid into the air intake, the injectors would get shut off but the ignition system keeps going. Maybe try this and see if it works. Just a thought.

Brian