1990 Pontiac Grand Prix - idles but wont go anywhere

IOWARHINO

MEMBER
1990 PONTIAC GRAND PRIX

I have a 1990 pontiac grand prix, 3.1 liter V6, with approx. 237,000 miles. The car has been running great until a few days ago. I was driving it on the interstate and it started to "cough, " and then it stalled. It will start right up, idle ok for a few seconds, then idle poorly but continue to run. The moment I put any amount of pressure on the accelerator, the car instantly stalls (whether in park or drive). I replaced the fuel pump a year ago, the fuel filter was replaced right after the problems (thought maybe it was plugged) and I have checked all the lines and it seems to be getting enough fuel all the way up to the engine. Can you tell me why it will start right up, but then stall when I press the accelerator? Thank you!

3 Replies

BMRFIXIT

MECHANIC
19,053 POSTS

Not enough fuel pressure
Check the fuel pressure with a gauge

Good luck

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Saturday, November 10th, 2007 AT 5:33 AM

IOWARHINO

MEMBER
2 POSTS

I checked the fuel pressure, gauge said it was normal. Couldnt figure out the problem so I took it to a shop. They checked the codes and it read two, one for lean exhaust and for MAP sensor. They replaced some broken vacuum lines, it worked for one day after that, then it went back to the same symptoms. They checked the TPS by scanning it and it was fine and have tried a few different things but cant get it to work, the mechanics are completely stumped! Anyone with any ideas would be greatly appreciated! (Once again, 90 grand prix with 3.1 v-6, will start and idle sort of rough but when you press the gas pedal whether in park, drive, or neutral it kills it instantly.) Thanks!

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Saturday, November 17th, 2007 AT 3:20 PM

BMRFIXIT