I had a racer swap a 5.3 in place of a blown up carb'd 350 and it doesn't seem to want to stay running. It started as a truck 411, so I just did a full flash of a 2002 Camaro 12212156 OS from the repository and deleted emissions. If i flash it it fires right up no problem and stays running and you can drive it on and off of a trailer. The 2 times he attempted to go out on track, it died before he could get from grid to the racing surface. From there on out, it'll start and die just as if the anti-theft weren't turned off. To make it run again, just reflash the same tune on and it fires right up. It is a returnless LS1 fuel rail and he initially dead headed the pump thinking that the dampener was the regulator. He ran to the parts store and picked up a Corvette FPR and hooked that all up under the car and it was still pulling this shit so I flashed his PCM for a corrected IFR to match the truck injectors he was running. This is a bone stock 02 F-body tune with emissions deletes, we're not allowed to play with fuel or timing in this class. I'm wondering if there's something else I missed in the tune? The motor is in a 3rd gen Camaro with a T5 trans. I've attached the current tune.

Matt Tune With 5.3 Injectors_0000.ctz

As you can see, I finally caved and updated to the latest software.