Pontiac Repair: 1995 Grand Prix SE engine problem, crank sensor, fuel starvation

Question
Hi Todd -

I have a '95 Pontiac GP SE (3.1L)sedan w/ 168K on it.It's been a GREAT car too!. But a week ago, it blew all the fiberlass packing out of the driver side resonator. I must've pulled 30 feet out of it after I realized it needed replacement anyway. Shortly after that happening, (and this may just be a coincidence), I started having problems with engine power and staling. Starts fine cold and runs OK, but after warming up, turning it off, it refuses to run well - it will re-start, but then die. After it cools down (maybe an hour or so, it'll be fine again until it warms up, the it just repeats that cycle. Tonight I warmed it up and revved it to about 4000 rpm - seems smooth and clear to that rpm, but then it stumbles and the rpm drops off. If I don't get off the accelerator, the engine continues to stumble around that rpm and it decreases in rpm until it would probably stop. I checked the MAF sensor visually for cleanliness and it looks fine - I plan to check the MAF voltages against RPM tomorrow. Would a totally empty glasspack resonator cause the condition? It is an original factory crossover, rather than true duals (from the left bank). (it connects into the right tailpipe at the rear). Or would I be better off looking for fuel starvation, O2 sensors, fuel filter, pump,etc? Unfortunately, I don't have a code reader, but it's the 12-pin OBD I connector which I think GM designated as OBD 1.5 (Won't spill the codes by connecting A & B together.) The MIL light has never come on though. I sense that's it's running rich, but can't really be sure (no black smoke). Any ideas? Thanks in advance for your help.

Answer
Hi Jim:

well that resinator may not be the issue but a plugged catalitic converter could do it. un hook the pipe and see if it runs with the converter off. You could have any number of things wrong with this and it seems heat related. It could be a crank sensor or an ignition module. when it quits running check for spark on all 6 cylinders. also when it quits running check the fuel pressure. It may not me a rich condiotion It could be a lean one and the engine computer is driving the mixture rich to compensate for a lean condition.