2000 grand prix stalls

2000 grand prix stalls

Welcome to AF

It would help to include the trim level and engine in your post.

Also, try to be a little more specific. Does it start then stall?, while driving?, coming to a stop?, randomly?,etc...

2000 grand prix gt 3.8

randonly

I merged your two threads. In the future, keep all posts in the same thread for the same issue. Just click on the thread name, then scroll to the bottom to add your new info. thanks

On your issue, can you please be more specific as to how the car stalls (at start up, randomly while driving, when coming to a stop, etc...). Also, when it stalls, does the tachometer drop to zero and the trac-off light come on just prior to stalling?

trac light does not come on

changed pump filter and relay

Do you have a service engine light that remains on when the car is running? If so, have you had the codes pulled?

engine light does not come on. Its just dies and the only lights that come on are the oil light and battery light

need help

I would suspect a crank position sensor, but since you say you get no tachometer drop to zero or trac-off lights (which almost always accompany a bad crank position sensor signal) I couldn't say . I'm sorry, but your symptom explanations couldn't be more vague, which makes it virtually impossible to narrow it down.

while driving it dies, no service light or trac light. wait a few seconds it will start back up and drive. eventually it dies again.

had a fuel pressure test done, when car is started,pressure dropped to 40 psi. thats when i changed the pump and filter. car still dies

When you first turn the key on before starting the car, does the service engine soon and other warning lights come on then go off. They should, as the car will do a bulb test at key on). If not, your Service Engine light bulb may be burned out or missing.

does it die even when driving at a steady speed, or only when accelerating/decelerating?

service engine light does come on at start, so it appears to work. the car will die while driving at any speed, and at idle. the tach is fluctuating at idle between 600 and 1000 rpm

ok, now we're getting somewhere.

with your idle fluctuation, the first thing I would try is unplugging the MAF (Mass AirFlow) sensor. When a MAF starts to fail, it will not trip a CEL, but will cause your symptoms. With the MAF unplugged, the CEL should come on (this is normal). If the car runs better with the MAF unplugged, then you need a new one. If it doesn't run better, I would take the IAC (Idle Air Control) valve out and clean it and the bore in the throttle body it rides in. Here is a link from our tips and maintenance sub-forum that shows a picture of where the MAF and IAC are located.

http://www.automotiveforums.com/vbulletin/showthread.php?t=746374

I hope this helps

Is there any reason for a fuel pump to have low pressure while ruuning, other then a bad pump

I just did another fuel pressure test, with the engine running it was at around 40 psi, would the MAF cause this

with the MAF unplugged its still running bad

The fuel filter could be clog, and can cause a low pressure problem, when is the last time you had the filter changed.

just changed the filter

never taken off a IAC is it straaight forward, or are springs and parts goin to go everywhere

richtazz thanks for pic

I just did another fuel pressure test, with the engine running it was at around 40 psi

Is that 40 psi at idle with vacuum connected or disconnected at the fuel pressure regulator? 40 is low. What brand gauge did you use? Check the highest pressure at fuel pump prime which is when you cycle ignition to ON, engine not running. Do it a few times and get the highest reading. Specs are 48-55 psi.

I took it up to the shop to do the pressure test, not sure what brand guage. It was 40psi at idle vacuum connected. i believe it was in specs. When turn the motor on the pressure seemed to drop

I replaced the pump with a used one from junk yard. so i dont know if its bad too. the pressure still seems low when running. so i dont know if i need to buy a new pump or if theres a sensor or something causing it to die

:shakehead

Well then the fuel pressure was not tested properly. Obviously the shop wasn't following the GM factory service manual. 40 psi is border line and on the low side for whatever reasons. I've never had a SII 3800 NA engine fuel pressure test read below 42-44 psi with engine at idle and the vacuum line connected at the fuel pressure regulator. With vacuum disconnected the reading will be much higher. The fuel pump prime pressure reading must be checked as I described in my prior post or the testing doesn't mean much or is inconclusive to rule out a fuel supply issue. Again that reading must be within a range of 48-55 psi.

Thanks BNaylor, i took it up there they said the pressure is low and i need a new pump. But since i just replaced it (used) i think the problem lies somewhere else. I dont wont to spend 250$ on a new one and be right back where Im at. Just lost and dont know what to do next.

Thanks everyone for the help. If anyone can make sense of why this car wont run, the help would be much appreciated.

Until you get the fuel pressure up within specs, you're never going to get the car to run correctly. As BNaylor stated, until you do a key on/engine off test it's hard to say if your fuel pressure while running is ok. It's on the low side, but taking in to account a margin of error on the fuel pressure guage being used, it still may be acceptable. If the key on/engine off test is the same 3-5 lbs low that your running spec is (45-52 psi), then the pressure guage may be off and your fuel pump may be ok.

Thanks Richtazz, lets say the fuel pump is good, I think it is. Could the IAC cause it to die and idle funny. If not, do u have any other ideas

What about the fuel tank pressure sensor?

The IAC could cause stalling at idle or low engine rpms. But if the stall is at higher rpms then probably not the cause but remove it and clean it just to rule it out. Be sure to clean the seat where the IAC mounts to the throttle body. Use throttle body spray cleaner.

Other suspect components could be the TPS (throttle position sensor) or crank position sensor even if no IP lights are showing or no DTCs with SES/CEL light.


What about the fuel tank pressure sensor?

Are you getting any evaporative emissions system DTCs?

2002 Grand Prix 3.8L with OBDII codes for MAP, MAF and Fuel trim rich

Hello, I have been having some rough starting, rough idle and stalling issues as well. I have done the following:
1. replaced the MAP
2. changed the IAC
It still had a stalling issue/rough idle.
3. changed PCV
4. cleaned my air filter (K&N) and cleaned the Throttle body.
The car ran fine for two weeks. Saturday I was at a stop light when the light turned green I pressed on the XLR8R and it stalled again.
5. purchased a dry air filter
6. changed front O2 sensor
7. replaced Fuel pressure regulator
8. cleaned MAF While removing the MAF I noticed that the silicone seal is not sealed properly. I found in another thread that this was an issue a guy had and replacing it fixed his problem. I just replaced this sensor 4 mo. ago so I am taking it back now and we will see what happens from here.
I hope you can use any of this and I will post back after I test mine with the new MAF later.

I am having similiar problems with my 2000 Grand Prix GT (3.8 L not supercharged). How easy is it to replace the Crankshaft position sensor.

I am having similiar problems with my 2000 Grand Prix GT (3.8 L not supercharged). How easy is it to replace the Crankshaft position sensor.

Not easy but can be done DIY. Visit our Tips & Maintenance forum which has a tech procedure. See link.

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=652664)

Thanks for your help. This is a great site, and I am just finding my way around. I didn't see anything on Ignition module replacement. Has this come up before?

I have replaced crank shaft position sensor and the ignition module. Everything was good for about 150 miles, and now it is doing the same thing. Any other idea's???

I have replaced crank shaft position sensor and the ignition module. Everything was good for about 150 miles, and now it is doing the same thing. Any other idea's???

Check for proper fuel pressure at the front fuel injector rail Schrader valve. No DTCs or SES/CEL light?

I checked the fuel pressure when problem first started and it is within spec. I don't get any DTC's or lights on. I am thinking it must be a loose wire somewhere, but it is hard to find.

I have a 99 gt 3.8, and its doing sort of the same things, its has a new fuel pump, and a new connecter to the power side of the pump. When driving, it cuts out and sometimes stalls. When it is tried to start again, the fuel pump wont turn on until you wiggle the wire on the pump. Dont know what to do anymore, and cash is tight.

Just to follow up my stalling problems were fixed when I took out the IAC and cleaned it.

My 2000 Grand Prix GT 3.8 ltr was randomly stalling. Idling, going down the highway, in town, low rpms, high rpms, it didn't matter. I got no check engine light, and it would start up right away again.

I failed my emissions test due to a faulty gas cap. Since I replaced the gas cap it has not stalled once. This was several months ago.

Just thought I would through that out there for the people pulling their hair out over this issue.

I'm really starting to hate this car. My husband and I have tried to fix this problem for that last 2 years. We have replaced all the senors, changed the crankshaft sensor, IAC valve, checked the wires, cleaned everything, changed the gas cap. It's a total mystery. I thought that the crankshaft sensor had solved the problem that only lasted a week. The car lags, when I step on the gas it's like it's being held back. When I rev it, it won't go past 4000 rpms. It seems to run fine on first start up. On second start up after a few hours of sitting that is when the problem starts. when at a stop it has Low idling and then stalls. Engine light and oil light(strange) comes on. No problem restarting it, but is a pain in the arse and dangerous when about to turn a corner. I can't believe there is no solution to this problem. Even the Pontiac dealers can't seem to figure it out.

Not Happy! :mad:

Welcome to AF!!

Have you done anything with the fuel system? If it lags it may be starving for fuel. Check the fuel pressure at the rail and check the fuel pressure regulator it may also need a new fuel filter. This sounds more like a fuel issue than anything else. Also it won't rev beyond 4000 due to the rev limiter built into the PCM.

A thread back from the grave.....

I agree with GTP DAD sounds like a fuel issue. check the fuel pressure before and after changing the fuel filter. check the voltage at the fuel pump to be sure it is getting enough voltage. Are you getting any codes? also FYI - aftermarket IAC and MAF tend to have issues

I have a 2000 Grand Prix GTP (supercharged) that has stalled on me but only once or twice. I baught this car about two months ago (from a private party) and for the most part it runs fine but recently has on ocassions run like crap. The engine light doesn't come on and the TCS light has been on sice I baught it. I took it to a friend to see if it has any codes that pop up. He gave me three codes 121, 203, and 303. After some research I'm not sure if I need to just replace the throttle position sensor and all is good, replace multiple parts, or just make a deal with the devil to get this car running good. I would also appreciate any information on prevenative maintenance so I can get this car running at tip top shape again with out having to sale my soul to the devil.

Welcome to AF!!

The codes indicate separate problems that need attention. First, the throttle position sensor will need to be replaced. Second check the wiring to the injector on cylinder 3. It could be a bad wire or a bad injector. Once you clear this up code 303 will probably go away since it is related to the 203 code. If you want to find out if the injector is bad simply switch it with another cylinder. If the misfire changes locations then the injector is bad and will need replaced. Good Luck!

I have seen several time a mouse or something makes a nest under the engine cover and chews up the wiring harness, Like GTP DAD said replace the TPS and check all of the wiring by injectors and harness .

Thanks!!

I have a 2000 grand prix gt 3800 series II not supercharged that stalls randomly. High and low rpm stalls also at idle. Starts right back up but dies within a second. You can lay on the gas once started and it just chugs and the fumes from the exhaust have an almost sulfur like smell. Car will start and run fine after a minute or two. But will soon do the same thing. Recently replaced fuel filter, plugs and wires.a any help would be greatly appreciated.

As you describe it it does make one think of fuel starvation. I'd look for a fuel pressure test....it installs on the fuel rail...should read and maintain 40-45 psi... If fuel pessure does not prove OK, voltage feed to the pump should also be proven right...I think wires to the pump come through the trunk bottom, right at the back of the seat...
..lots of components can be involved, : pump relay, wiring, the fuel pump itself...I do not have the wiring specific to that odel but if they kept their former year design, the 12V feed to the pump is also backed up through a contact on the oil pressure sensor...
THe fact that is can start "instantly" indicates the fuelpump relay operates....but it happens worn out relay contacts cannot maintain heavy current for long..anyway tsting for steady 12V + at the fuel pump and fuel pressure test must make or clear that fuel supply issue
...come back to discuss results...