[jim_howard_pdx]

If resetting the computer and checking all your wiring doesn't fix it, pull the distributor and have it replaced.

I too had a bad distributor once that allowed me to fire up and run to about 4k. It was rough, but it was running. Then anytime I tried to tip in the throttle it would go way rough, flatten, struggle andd even mimmick back firing. The rebuilt distributor fixed this for just 16 bucks.

Also, if you are running a roller cam, you must change the distributor gear to steel or bronze. The cast iron gear factory gear will get worn away by the steel cam gear and you will end up with scorched bearing and journals. You should make sure to ask for a distributor for a roller cam year mustang, that way you should get the right one. But double and triple check this detail. This is very important for all of you out there. Know what kills your car fast! This is one of those things.

Good luck and let me know what works to fix the problem.