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2001 pont. grand prix 3.8l

01-12-2010, 09:54 AM
I have a prand prix that won't Idle>I have replaced the iac, throtle positioning sensor, crank positioning sensor, spark plugs, plug wires, fuel filter, and cleaned out the intake,,and you guessed it, it still won't idle. Everyonce in awhile it will idle for a little then it dies, then you have to pump the gas while cranking it and she will run for a few minutes and die.I know it has a small exhaust leak on rear engine but am trying to wait for warmer temps before digging into that...please help i have no way of getting it to a shop to read codes right now because i am in the boonies of montana.

01-12-2010, 10:18 AM
Try starting with the MAF sensor unplugged.
Can you hear the fuel pump run?
Check for fuel at the fuel rail, check the pressure if you can.

01-12-2010, 10:24 AM
if you unplug the mass air flow the car smokes and service light goes out, until you plug it back in, fuel pump you can hear, how would i check fuel pressure without gauge?

01-12-2010, 11:20 AM
Are you saying it runs with the MAF unplugged? Is the smoke black or white?

01-12-2010, 11:23 AM
ya i am sure it was maf we replaced it last year and it is kind of gray smoke and makes the car smell like a 2cycle when you unplug it. but you have to force it to make it run

01-12-2010, 11:39 AM
So it sounds like it runs the same with or without the MAF sensor.

You need a gauge to check the fuel pressure They run $30 - $40 IIRC. There a port on the fuel rail with a cap on it. Remove the cap & you'll see a Schrader valve, they look like a tire valve. Turn the key to run a couple times then press in the center of the valve. The fuel should spray out. If it just dribbles then you could have a bad pump or frozen fuel line.

I'd also check the 3 front spark plugs after it starts & stalls. See if they're wet or dry.

01-12-2010, 12:09 PM
the fuel will squirt at first then dribbles. plugs are all dry if you hold it above 2599 rpm it will stay running

01-12-2010, 12:59 PM
It's normal for it to spray & then dribble as the fuel pressure drops. That combined with the fact that it does run above 2600 probably ruels out fuel pump problems.
Have you checked for vacuum leaks?

01-12-2010, 02:04 PM
have tried looking for vacuun leaks but haven't found any. could the egr a cause of this. It has a new cat on it after last winter i had to force it back to montana when the cat decided to go out on me. I have cleaned the egr and everything but I know they still have a tendency to fail?

01-13-2010, 06:42 AM
you state 3.8, but didn't say SE, GT or GTP? Which model is this?

01-13-2010, 09:14 AM
it is a gt sedan

01-13-2010, 11:05 AM
Have you double checked the spark plug wires are going to the correct cylinders? Standing in front of the car & looking at the engine the front cylinders are 1,2,3. The rears are 2,4,6.

01-13-2010, 01:50 PM
yep checked plugs over 3 times and there all in order

01-13-2010, 01:51 PM
drove it to the gas station and back 20 min trip did fine tell lats 4 minutes then kept trying to die on me had to keep idle above 2500

01-13-2010, 02:05 PM
if you unplug the maf un plug back in service light goes out. after i got more gas init today on my way home the service light went out and then it was trying to die on me. if you pump it a little it will let you go a little further then you have to do it all over again and you can pump the gas to keep it running while it is sitting usually during first start of the morning it runs great. just checked fuel pump tore out back seat and you can hear the fuel pump running,,is there a cell in the fuel tank that could be causing this?

01-13-2010, 03:45 PM
Pull the vacuum line off the fuel pressure regulator and turn your key to on but not start and check for gas dripping out the vacuum port.

01-13-2010, 05:09 PM
i had a similar problem last year. it ended up being the fuel pump resistor. apparently the pumps on our cars have two speeds. i think what i was told is when the resistor goes, the low speed goes. around 2600 might be where the high speed kicks in and if it dies when you keep it under 2600 then it would make sense to me.. but i dont know. anyone have any thoughts on that?

01-14-2010, 09:34 AM
so what would you do to replace the resistor

01-14-2010, 10:03 AM
when it does run it has a nasty smell like when you do a injection clening onit, like rotten eggs, maybe clogged injectors?

01-14-2010, 10:33 AM
I thought just the supercharged engines use the fuel pump resistor, someone please confirm.
The rotten egg smell is usually associated with a faulty cataytic convertor. Try to give it a shake & see if it sounds like marbles in a tin can.

01-14-2010, 10:38 AM
when it does run it has a nasty smell like when you do a injection clening onit, like rotten eggs, maybe clogged injectors?

Yep the fuel pump resistor is only for 97-00 GTP's with two speed fuel pumps.

Sounds like your car is running rich. Have you checked for fuel in your fuel pressure regulator vacuum port?

01-14-2010, 03:04 PM
connect vacuum pump to intake manifold somewhere and check intake manifold vacuum. If you can get her to start and run on her own for 5-10 sec then tell us what vacuum you measured.. Remove egr and plug the intake hole with your hand try to start the engine see if it works any better.

01-15-2010, 08:22 PM
ok i got the car to autozone and they cleared the codes and now it comes up with code for the egr but car won't run unless mass air flow is unplugged.

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