Tbi timing guru’s for cold stumble issue

[Billyworld]

Please tell me if i should start my own thing. Are all proms the same from the factory? All other things being equal of course. I have the opposite problem, as mine runs great when it's cold however not so good when warm. I'm also putting out that black water junk that's hitting the pavement. Crate 5.7 TBI

 

[bp71k5]

Please tell me if i should start my own thing. Are all proms the same from the factory? All other things being equal of course. I have the opposite problem, as mine runs great when it's cold however not so good when warm. I'm also putting out that black water junk that's hitting the pavement. Crate 5.7 TBI

If it runs bad when warm, it’s probably o2 sensor related, or EGR. You’re prom is probably fine unless the engine has always acted bad when warm

 

[dyeager535]

Please tell me if i should start my own thing. Are all proms the same from the factory? All other things being equal of course. I have the opposite problem, as mine runs great when it's cold however not so good when warm. I'm also putting out that black water junk that's hitting the pavement. Crate 5.7 TBI

All PROM's are not the same. GM standardized as much as possible, but for every drivetrain combination, there was a specific PROM.

If this is a stock ECM, in a stock application (IE, the correct ECM/PROM for that specific truck) and a factory replacement engine, with no modifications, then it should run like it did from the factory.

 

[RubberFloorMat]

I haven’t played with TBI in awhile but it sure sounds like Coolant Temp Sensor. Unplug it and see what happens.