was tuning an 02 6.0 lq4 with a good sized cam 232 240 i believe, and the truck idles fine both park and drive, but as soon as i barely and i mean barely like 1% tps type of stuff, the truck dies immediately. The truck is on open headers right now, but shouldn't really matter. Anyone has had this problem? could be a fuel pump not sure yet.

 

What does timing do?

 

What tuning software are you using? Does it trip any codes, or does reduced engine power pop up on the driver display? Can you cycle the accelerator through the full range of motion with key on engine off without it tripping anything?

 

im using hptuners, the truck idles but the stit are at 150 lb/hr and the RAF are at 5.3 lb.min.. the truck has a p0200 but the injectors are fine.