2003 Le Sabre 3.8 Series II Starts, runs fine then dies after a few minutes

[sniper60]

It will start fine, run great for a few minutes and then stumble and die. Checked fuel pressure after it died and was only getting 12 psi, everytime you cycled the pump with the key the pressure would creep up a little. You couldn't hear the pump run before I replaced the pump and you can hear it run now, but it still dies after a few minutes. Also had a bad fuel pressure regulator/egr vacuum line that was replaced. It will restart, rev and die with half, or better throttle, after initially dying. Cleaned the MAF with no change. It runs great until it starts to warm up. I'm ready to pull my hair out, as I'm not the best with these computer controlled cars. This initially happened in a drive through and found the cracked vacuum line, but after replacing it the problem remained. It also has a very nasty smell from the exhaust after it dies and I try reestarting it, not "egg smell", but not right either. I can't describe it, but it's pretty rank. Any help would be greatly appreciated!

 

[HotZ28]

It sounds like you either have a gas leak from the pressure regulator, or coolant leak from an EGR/UIM, or LIM coolant leak. Have you checked the plugs to see if they appear flooded/wet?

 

[sniper60]

It sounds like you either have a gas leak from the pressure regulator, or coolant leak from an EGR/UIM, or LIM coolant leak. Have you checked the plugs to see if they appear flooded/wet?

No, not yet. That is next on the list of checks. I've been pretty busy and plan on doing that tomorrow (plugs). When I replaced the vacuum line for the pressure regulator and EGR there didn't appear to be any fuel in the old line, or the regulator. The coolant level has been steady and I haven't had to add any so I hadn't given that much thought. I had a 2000 Bonneville years ago that had the IM leak and it hydrolocked the engine. That explained the coolant I had to add to that at the time. I will report back once I check the plugs and regulator line again. Thank you for responding and have a great day.

 

[Homer Jay]

Could be a failing MAF, especially if it has been previously replaced with a non OEM. Disconnect and see if that helps.

 

[sniper60]

Could be a failing MAF, especially if it has been previously replaced with a non OEM. Disconnect and see if that helps.

I cleaned it with some MAF cleaner, is there a way to diagnose it?

 

[HotZ28]

I cleaned it with some MAF cleaner, is there a way to diagnose it?

How To Test The MAF Sensor (GM 3.8L V6 1996-2005)

GM 3.8L Index of Articles

easyautodiagnostics.com

 

[HotZ28]

What is the fuel pressure with the new pump?

 

[sniper60]

How To Test The MAF Sensor (GM 3.8L V6 1996-2005)

GM 3.8L Index of Articles

easyautodiagnostics.com

Thank you for the link sir. I don't know if I mentioned that this only happens after the engine starts to warm up, suggesting to me that it's it's an electrical issue, but spits, sputters and dies like a fuel issue. I used to wrench back when computers weren't a thing, let alone in cars and I'm not the best at computer issues. Again, I appreciate your input and assistance.

 

[sniper60]

Okay

What is the fuel pressure with the new pump?

Fuel pressure with the new pump is at 58 PSI. I checked the FPR again and let it run for 3-5 minutes, that's all she'd go before she died. No fuel coming from the regulator and no evidence of fuel in the vacuum line; visual, or odor; when I removed it. I replaced the plugs and wires also. They were rather carbon fouled and both the wires and plugs appeared to be OEM (124,000 miles). I just received a proper DMM to test the MAF sensor today, so I'll be doing that later, if I can get it to run long enough. My son and I disconnected the EGR when it started running like crap and it did run marginally better, but still very bad. Surging, stumbling, inconsistent idle and then dying. It will sometimes run somewhat normally if, you keep the revs above 3000, but then you get a nasty "egg" smell from the exhaust and it blows a little bit of black smoke out the tail pipe. It will die as soon as you get off the gas pedal, even slightly, though. Cold, it runs like a brand new engine. It seems to be fuel related, but only once it starts to warm up. We also put a spark tester on each lead when it started running bad and it appeared to be sparking consitently. I'm not one to pull out the parts cannon and would like to figure this out before buying anymore parts. There are few things left to rule out; MAF, MAP, FPR (doubtful) and the EGR (also doubtful). Have I mentioned my love/hate relationship with all things computerized, lol?

 

[HotZ28]

Keep us informed of any progress, or solution. Good luck!

 

[G-297703]

It will start fine, run great for a few minutes and then stumble and die. Checked fuel pressure after it died and was only getting 12 psi, everytime you cycled the pump with the key the pressure would creep up a little. You couldn't hear the pump run before I replaced the pump and you can hear it run now, but it still dies after a few minutes. Also had a bad fuel pressure regulator/egr vacuum line that was replaced. It will restart, rev and die with half, or better throttle, after initially dying. Cleaned the MAF with no change. It runs great until it starts to warm up. I'm ready to pull my hair out, as I'm not the best with these computer controlled cars. This initially happened in a drive through and found the cracked vacuum line, but after replacing it the problem remained. It also has a very nasty smell from the exhaust after it dies and I try reestarting it, not "egg smell", but not right either. I can't describe it, but it's pretty rank. Any help would be greatly appreciated!

That nasty rotten egg smell that you're smelling is a cadillac converter, completely plugged got it out or take it off.You will find out that it runs perfectly. You could disconnect your buffer right before it.And I'll bet you it keeps running.Then you'll know