Running Problem: 1992 Oldsmobile: Fule

I have a 1992 Oldsmobile Cutlass Supreme 3.1 V-6, my issue is---I can drive it from point A to point B---no problem, I can shut it off and if I start it right away it starts right back up but if I give it 15-30 minutes it won’t start, it cranks, it’s getting gas but it just won’t fire. Then sometimes it will fire but it runs rough---REALLY rough! But if you let the motor cool completely down then it starts right back up again and runs fine until the next time it’s been driven far enough to get the motor hot. It has a new fuel pump, which was put on about three months ago. I’ve changed the map censor, replaced the catalytic converter, put in a crank censor and changed the ignition model. Now I’m at a loss, a few months ago I changed out fuel rail and injectors but they were off of another car. Any help would be greatly appreciated.

Welcome to AF, get a fuel pressure gage on this for starters and look for 35-40 psi.

Thanks for the welcome and it's 40

Ok, when it won't fire do you have spark, and injector pulse?

I'd Like to thank you for your help. It turned out to be a bad fuel injector…