Intrigue engine shuts of after warms up

[SerenityRiver84]

Hi

Here's my problem:
I have an Oldsmobile '99 3.8, 130K miles. At first the car would shut off when coming to a complete stop. We hooked up the scanning tool to it, it read faulty MAF sensor. So it got replaced, along with IAT, ECT. Now the car will run when it's cold, and warm up and run until the gas runs out. Although when it warms up and it gets shut off, and trying to start it, it will start and die within seconds.

The ignition module is fine, fuel pressure is fine, battery/cable fine, brand new plugs and wires,fuel pump is fine. I have read in a lot of forums that there's a security feature with this car. When I bought this car, it was in a front end collision, and I believe the ignition system was changed. Reasoning: The key is not chipped, like my Buick or Taurus, and there is not security light that flash like my other two cars. This car has been running fine for almost a year and now this.

We are pulling our hair out trying to figure out what's wrong with this. I hooked up the scanner, there are no codes. I'm starting to think it might be the PCM? EGR? or something else. Please help.

-Katie

[fhofstra]

Katie -
Here may be a couple things to consider. If any of these suggestions make sense, search the forum for that item/subject, and you should find a lot of data. Truth in advertising here - I have a 3.5 (2000), not a 3.8 on my car.
1. If I understand you right, you are saying that the engine starts OK when it is cold, and continues to run properly until it is turned off. By "until the gas runs out", I assume you mean "until the tank is empty". So you could go 300 miles without a problem, as long as the engine stays running. But that if you then try to start the engine when it is warm, it will start, but then will immediately stop (not stay running). And then if you let the engine cool, it will start and run properly again, until the hot engine is turned off.
2. FPR (fuel pressure regulator)? Fuel filter?
3. You said fuel pressure was good. Did you / can you put the pressure gauge on the Schrader valve (my 3.5 has one) and watch real-time what happens to fuel pressure when you are having starting/running problems?
4. I had an IAC (idle air control) cause my engine to fail to idle. However, it still started, as long as I held the throttle open.
5. There are a lot of posts about security circuit troubles. If your ignition system was "changed" (or do you mean "replaced" with identical, factory-stock parts?) the sky is the limit.
6. If it is a thermal problem, they are tough. But if it is, all the hot components continue to work, until it is time to restart the car. That would narrow down somewhat, which components it could be.
7. If the failure is reliable, it might be time for a shop/dealer to monitor a warm restart (since that is specifically when you have the trouble) with the famous Tech II diagnostics equipment.

Hope this helps...it's all I can think of.

[LittleHoov]

I dont think any Intrigues ever had the "chip" in the key. I know my 2000 does not, but it would be nice if a 3.8 owner would chime in here...

I rode with a girl a couple times who had a 98, but lets just say I never noticed whether her key had a chip in it or not....my attention was elsewhere...but I digress.

I think if it was a Security issue, you would have the flashing light as you mentioned.

These sort of things can be caused by a Crankshaft Position Sensor that is getting a little moody. But I hate to tell you to replace it, thats sort of just throwing money at it and hoping to get lucky.

Checking fuel pressure while its acting up is a GREAT idea, and might really help shed some light on things. When its shutting down it has to be either losing spark or fuel, and spark is going to be tough to test.

[dtownfb]

I'm with LittleHoov. This sounds like the CPS is acting up esp. since you have checked the ignition, security, fuel, etc.

BTW, what code were you getting?

[SerenityRiver84]

Hey thank you so much for your advice, I went out and finally got a fuel pressure gage, and TA DA found the problem. It's the fuel pump, I heard it's possible for the fuel pump not to work after the car warms up, and there is an erotic fuel pressure. At first turn of the key, the pressure drops from 50 psi - 40 psi and when turning on it drops to 36 psi. I am so happy I found the problem, I was about to push this car off a mountain but there are no mountains where I live lol

[SerenityRiver84]

Checking fuel pressure helped a ton! It made me find the problem which is the fuel pump.
P.S. keep your eyes on the car next time lol

[LittleHoov]

Well I hope Im not the bearer of bad news, but to me, 36psi should still be enough to at least start the car, and more than likely run it....

But I could be wrong, I dont know what specs its supposed to have. Did you look up the specs for a 3.8?

[cpberry1]

Originally Posted by SerenityRiver84

Hey thank you so much for your advice, I went out and finally got a fuel pressure gage, and TA DA found the problem. It's the fuel pump, I heard it's possible for the fuel pump not to work after the car warms up, and there is an erotic fuel pressure. At first turn of the key, the pressure drops from 50 psi - 40 psi and when turning on it drops to 36 psi. I am so happy I found the problem, I was about to push this car off a mountain but there are no mountains where I live lol

I can't resist...
It seems that if the problem is erotic fuel pressure after the car is turned on a simple solution might be a cold car wash!
On the other hand, if it's erratic fuel pressure you were referring to then I agree you're on the right track with the fuel pump or delivery system.
All in fun...

[dtownfb]

Originally Posted by cpberry1

I can't resist...
It seems that if the problem is erotic fuel pressure after the car is turned on a simple solution might be a cold car wash!
On the other hand, if it's erratic fuel pressure you were referring to then I agree you're on the right track with the fuel pump or delivery system.
All in fun...

You beat me too it.

Could the problem also be the fuel pressure regulator?