I have a question for you lt1 pro's. My lt1 seems to be having a issue that comes to part after warming up. It will run perfect for about 10 minutes then it starts idling down lower and lower to the point that it almost stalls out and responds very poorly to throttle postion it will hesitate and backfire. Then if you shut it down it seems to run fine for a few moments and then continues to do this. The car has no egr and a reworked ecm. It acts like it has fuel or timming issues. Need any input. Thanks

 

Sounds like you are having a problem running in closed loop for some reason.

 

It does have a closed loop problem, It does not like to go into closed loop at all.The only way I can get it to go closed is to hold the gas down and steady at about 1200 rpm then it will go closed.

It acts really funny it hesitates real bad like a rev limiter then after a few seconds will open up and run hard and good, Then only to come down off of idle and seem to run really rough.
I had the ecm worked on and some things were tweaked it wants to idle at 550 in gear, is that a normal setting? I really feels like it gives it a bad lope in park it runs at 650. I never drove it with a stock ecm program and have no idea if I am having a program problem or a sensor running amuck?

Also while holding the gas at lets say 1500 rpm the engine will lope down hard then speed up on it's own or viseversa?