2005 won't stay running. Rough idle. New MAF?

Discuss your 2000-2005 Bonneville SE, SLE, SSEi, Buick Le Sabre 00-05 and Buick Park Avenue 97-05. Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.
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Ludichris
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2005 won't stay running. Rough idle. New MAF?

Post by Ludichris »

Here's the scenario:

First off, I've had the car for about 40K miles. It's never exhibited even close to this behavior before. Let's rule out some things: I pulled the air filter (K&N high flow), and it looks fine. Plugs and wires have about 35K on them or so. Just did a fresh oil change, as well as tranny fluid and filter change (not that the tranny fluid or oil has anything to do with the info, but just giving the info). I cleaned the throttle body and MAF 40K ago when I first got the car, and it's ran fine up until yesterday.

So, yesterday it was about 88 degrees (warmest day so far this year here! YES!). I had about a six mile commute between work and where I was going (band rehearsal). Started it up about two hours later....and it cranked just fine, stayed running until I threw it into reverse, and died. The next 30 minutes consisted of starting, restarting, and restarting yet again. As long as I kept my foot on the accelerator (+/- 3000 RPM's), it ran. Take my foot off the accelerator, it shut off instantly. VERY rough idle, sounded like it was about to backfire (but never did...came close though I think), a little white smoke coming out the tail pipe, the smell of gas in the cabin, almost like it was getting flooded or something, and erratic RPM's. I pulled the little hose off the fuel pressure regulator (not sure why, just trying things that were easy to try), and it at least stayed running the first time I tried that, but still the erratic RPM's, and seemed to idle a little high even when the engine temp was at about 160 degrees (I couldn't get it running long enough to get to full temp). At that point, it was running at +/- 900 RPM's or so....a little high for this engine.

Anyway....I couldn't get it home, it stayed in the parking lot. I'm about to go over and pull the clip on connector from the MAF and see if it smooths out, but I'm wondering if there's anything else I should look for/check. Any help is appreciated. OH, and I've been getting GREAT fuel economy - 33 MPG on my last 80% highway tank. OH, and I can hear the fuel pump whirrrrr up when the key is turned too. That's all I got. Advice?? Is it probably the MAF? I'm hoping so, 'cause that's easy and relatively inexpensive. Thanks all!
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Jfridge92
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Re: 2005 won't stay running. Rough idle. New MAF?

Post by Jfridge92 »

You can try to test the maf by unplugging it and running the car. If it runs better then replace the maf.
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MrPOPE
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Re: 2005 won't stay running. Rough idle. New MAF?

Post by MrPOPE »

Always suspect the MAF first on these cars... disconnect it like Jfridge said and test it out
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Ludichris
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Re: 2005 won't stay running. Rough idle. New MAF?

Post by Ludichris »

Yup, it definitely was the MAF. Did the un-plug test, and it was interesting. I started with the MAF still plugged in, and it started right up, and stayed running. I was just curious whether it would or not, but the engine was cold, so it doesn't really count. Unplugged the MAF. Let it get up to operating temp. As soon as I plugged the wiring harness back into the MAF, the engine died. I tried this a couple more times. Unplugged the MAF, started it right back up, and it kept idling....plugged the MAF back in......killed the engine immediately. So...I got a new MAF, it was an easy fix, it's purring like a kitten again, and I'm happy. Thanks for the responses guys, I appreciate it!
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