Originally Posted by Bobs36ford
He said it only backfires after warming up on road driving about 60 mph
Is the module the same as a rotor.
I had a car with HEI it would run fine till it got hot then start crapping out turned ou to be a bad moduale and ran fine after it was replaced. after a while it would stop running until it cooled off then I could start the car again and drive til it got hot again. Looks like it happens all the time. If you have had the car for a while and have not changed it its time. i change them out with the wires and cap now since they are so cheap. Orginal gm units are actually the worst since everyone has made an updated part now best to go aftermarket. I think a/c delco has a new part number as well. but not sure if theyh support higher rpm and stronger spark like the aftermarket ones do.
Coil and wires can also be good suspects. Along with chalking on the distributer cap contact parts.