Car sputters/stalls without warning

[TazMan]

Hello again everyone. I've got a 3.1L 92 Grand Prix that just sputters and sometimes dies without and kind of pattern or warning. The car starts right up and drives fine but eventually the car will start acting up. It doesn't seem to matter whether I am cruising or accelerating hard but it happens with my foot on the gas. Sometimes it spudders violently for a short minute and continues. Sometimes it spudders and stalls. Sometimes it'll just seem to slow up a bit and I have to hit the gas harder, and occasionally it will just plain stall. When it spudders violently, it almost feels like I am pushing the accelerator and turning the key on and off. It can happen 5 seconds or 2 hours into driving. It has always started right back up until yesterday. It died and wouldn't start. I pulled over, and a minute later it was fine and continued to drive fine for the rest of the day. On the highway it's usually okay. It will sometimes but rarely slow up while cruising requiring me to give more gas then I should have to, but it doesn't die on the highway. I've been listening carefully for any kind of backfiring but have heard none. I do notice when I remove the gas cap there is a hiss of air releasing louder than any other car I've ever owned but I don't know if thats normal. Any idea's? Thanx so much everyone for taking the time to read this and sorry the post is so long. I wanted to include everything that I thought might be relevant.

[3100 MPFI]

My STE was doing that, and it was a problem with the fuel pump. Not sure if that is your problem also, but replacing the pump on my STE fixed it.

After your car has sat for a few hours, does it start right up, or is it sometimes hard to start?

[TazMan]

Thanx for the reply. Actually the car almost always starts right up. There was one time about a week ago that it died and didn't want to start up again. It was very hard to start and when it did start, it died almost immediatly afterwards. 10 minutes later it was fine. Aside from that one time, the car usually starts right up with no problem.

[xbornkilla2k4]

i got a 94 grand prix 3.1L and mine does the same thing... sometimes if it starts doing that i put it in neutral and the idle will bounce to about 2k rmp for about 5 sec. and go back no normal idle and i can put in back in drive and continue on my way. its does this about once every 3 weeks and has been doing it for about a year so i have no idea.

[bszopi]

Could be the IAC sticking...

[PCGUY112887]

Try checkin the fuel pump, mine did similar and I had it towed becuase I was afraid of it diein while tryin to get it to the shop. The guy hooked up a guage to the fuel rail and you could see it bouncin around, then it would bounce around a lot right before it would die.

I suggest checking what sort of pressure you are getting. I know with my 3100 i'm supposed to get 40-45 and it was reading 30-35, yours should be similar.