GP just shuts off

[AdamIPFW85]

Got a 2000 GT with 83000, I got it out of storage this winter and when I start it, it dies with in a second or two. However, sometimes it just won't turn over for a while, but that hasn't happend in a couple weeks. Now it just won't stay running, NO MATTER what the RPM is at. I have had it at full REV still just shuts off. I tried changing the IAC but it still did it this morning. No codes or anything. I found that if I turn the key back to OFF and then try again it starts right up. Other than this, it runs like a champ. ANY IDEAS????

[BNaylor]

Have you changed the fuel filter? Sounds like a fuel supply issue. Check the fuel pressure at the front fuel injector rail. There is a Schrader valve at the fuel pressure regulator where you can connect a fuel pressure gauge. Should be 48-55 psi. Check at fuel pump prime since you are having difficulty keeping it running. Ignition to on not start. Also, you should hear the fuel pump prime for a couple of seconds.

The other possibility is the MAF sensor so disconnect it to rule it out.

[AdamIPFW85]

I just changed the fuel filter last year before I put it away. It has to be something that gets reset when the car is turned off and the key is turned back. So its got to be a sensor. That MAF maybe it. Seriously, after it starts runs fine never know anything was wrong, good response and power. It doesn't do it everytime, probably 1 out of 10 starts if that. Its not really a problem, just a hassle and I don't want it to get worse. Anyother ideas let me know.

[daejuanj]

When the car dies, does any of your console warning indicators show?

[AdamIPFW85]

When I start it, it will run normal for a second or two. Then it literally is like u just turned the car off, no matter what the RPM is at. U can here the air suck in the K&N filter and everything. It is either electrical, or electric fuel wise, like a tricky fuel pump. Cause it will just reset itself after being shut off for a while. But it isn't coding for anything. To answer ur question the dash lights come on just as if you turn the key to the ON position. Now that I think about it the SECURITY light will stay on sometimes after starting it, but it doesn't really correlate with the trouble of starting. Its just something that it started doing after I had the starting problem.

[tblake]

keep your eye one the DIC when it shuts off. Does the "Trac Off" light come on when it stalls? If so, replace the Crank Position Sensor.

[AdamIPFW85]

Nope, I'm telling u guys, It is 100% identical to just shutting the car off, by turning the key back. U seriously couldn't tell the diffrence. Nothing unordinary happens except it just dying. No wierd lights, nothing. The only other thing that has came up, is the SECURITY light stays on sometimes, but it seems to have no relationship. Thanks for trying to help everyone, let me know if anything else comes to mind. The only status update is that it is getting harder to get to come out of its funk, but again once it is starts it runs fine and wont do it again for awhile.

[tblake]

Man, it sounds so much like a failing Crank Position Sensor. I had mine fail at about that exact same amount of milage.

When it stalls, it will crank for some time befoer it restarts? Why not check for spark after it stalls out? Remove the plug wires from the coil packs and have an assistant crank it. Observe the coils and watch as the motor cranks. You should see and hear sparks dancing between each coil. If you dont, you know the problem is ignition related, and you can rule out the MAF.

No spark, then consider replacement of the CPS. Its only a 50 dollar AC Delco part and quite easy to replace on the 3800. There's a tech article in the Tips and Maintenance subforum. I did mine in about an hour and a half.

[AdamIPFW85]

Wouldn't that give me problems also while I am driving? This is just at start up.

[tblake]

Nope, a CPS when fails will just cause the car to drive perfectly fine, then just stall out of no where. Sometimes restart right away, sometimes have to sit a few minutes before it restarts. When it starts it will run perfect again. Usually a bad one will not trip any DTC fault codes, so ususally it wont trip the ses light.

[daejuanj]

Originally Posted by tblake

Nope, a CPS when fails will just cause the car to drive perfectly fine, then just stall out of no where. Sometimes restart right away, sometimes have to sit a few minutes before it restarts. When it starts it will run perfect again. Usually a bad one will not trip any DTC fault codes, so ususally it wont trip the ses light.

This is the exact same thing problem I was having with my car. Took it to the shop, they thought it was the Crank Position Sensor. That didn't fix the problem. I figured out if was the MAF sensor.

Just disconnect the MAF. When you start it up at first, it may run a little rough for a minute or two, but will run fine afterwards.

This is an easy, and free diagnoses. Since replacing the CPS is a pain.

[AdamIPFW85]

This doesn't run rough before it dies, it just stops. Like turning the key off. I took it to my shop yesterday to get radiator flushed. I asked what he thought. He came up with Fuel Pressure Regulator. This Sucks

[BNaylor]

Originally Posted by AdamIPFW85

I asked what he thought. He came up with Fuel Pressure Regulator. This Sucks

All you have to do is run a fuel pressure check as suggested earlier which checks out the fuel pressure regulator operation. Expensive part to be replacing without proving it is bad.

[3echo9]

Originally Posted by tblake

keep your eye one the DIC when it shuts off. Does the "Trac Off" light come on when it stalls? If so, replace the Crank Position Sensor.

Along the same line of thinking doesn't a bad Camshaft Position Sensor have the same symptoms as the Crank Position Sensor? Only a bad Cam Pos Sensor will allow the engine to start where as a bad Crank will not?

Just a thought.

[tblake]

it will, good point, but doesnt a bad cam position sensor cause extended crank times as the PCM defaults to just the crank sensor signal? Also when it starts I think it will trip an ses light.