I?ve got a 1990 v10 5.7 Blazer that we have recently done an engine swap in. We had about 150 miles on it, now it wont start if its warm. The engine will only start when it?s cold, and then it will get to temp and run rough for a few seconds and die. Tonite we tried to reset the ECM by unplugging it, we got it up to running temperature when it started to sputter, so we would rev it/maintain a high RPM. It would keep running but it was running extremely rough and the exhaust smelled rich with gas. When we let off the gas it died. Strangely enough from the Catalytic Converter back was bright red. We never noticed it during the day, but now we are completely stumped. We figure it has to be some kind of computer, we have replaced the distributer, ignition control module, the coil, the O2 sensor, and the throttle body was rebuilt.
Something makes us think its the Air/fuel Ratio that is flooding it once it warms up.
Any advice would be great.