[twobjshelbys]

I had the same problem with my Roush 427IR. Mine was the Accel system. They had not done the high altitude compensation setup. I shipped the car back to them in Detroit and they said it ran great, got it back to 6000' and it didn't work. Finally took it to an Accel tuner (not Roush) that had been trained on high altitude setups. Ran great after that.