MAF sensor crapping out - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


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Old 05-29-2006, 12:32 AM   #1
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Default MAF sensor crapping out

My rpms have been moving around some while I'm coasting in my car and my idle has been a tad on the rough side. So today I had some time so I pulled the sensor and cleaned it per directions in Tech info seems like it helped some but not enough. I got some dirt off of it, but it appears I do need a new one. I tried to find one on GMPD but the part # turnd up nothing. I was wondering where is the can I buy a good quality replacement for online? Or anyother place that would be cheaper then in store retail?

Ed
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Old 05-29-2006, 12:34 AM   #2
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Let'* get more specific. Why do you think it'* your MAF sensor as opposed to any one of 12 other things that can cause that? Most notably a vacuum leak?
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Old 05-29-2006, 12:37 AM   #3
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Default Re: MAF sensor crapping out

Quote:
Originally Posted by McGrath
My rpms have been moving around some while I'm coasting in my car and my idle has been a tad on the rough side.

What do you mean by moving around while coasting? Like a good 500-1000 RPM fluctuation?

If that'* the case, once in a while I have the same issue, especially coasting down hill. When the RPM'* drop and the trans will slow down the car, then all the sudden the idle kicks up and the car almost feels like it'* free wheeling?
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Old 05-29-2006, 12:50 AM   #4
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My boost gauge reads -10 at idle and doesn't move (I know the stock boost gauge isn't the most accurate around), my vac lines look pretty good. I recently replaced a dry rotted connector but that was for the evap system. What else could be causeing my rpms to drop & then rasie again while coasting?

Ed

Lakeville It doesn't move more then 1k nor does it feel like the trans is slowing the car down. Speed at which I'm moving doesn't seem to affect the rpms moving around much, except when I'm on the freeway it'* not so noticeable. The rpms will normally drop then not even a second later they pick back up, It acts like the engine is starved for air for just a split second.
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Old 05-30-2006, 12:41 AM   #5
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bump

Could anyone suggest any other things to check out before I go spend $ on something that may not even be bad?


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Old 05-30-2006, 12:46 AM   #6
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Quote:
Originally Posted by McGrath
My boost gauge reads -10 at idle and doesn't move
Big one there. The Series 1 L67'* only got a MAP sensor if they had a boost gauge (SSEi'* only). But the Series 2 uses it for a boost reading AND PCM feedback. It'* a critical sensor used to determine engine timing advance and other important crap.

You either have a disconnected, faulty, or leaky sensor, or your boost is constantly in bypass.
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Old 05-30-2006, 10:43 AM   #7
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This isn't the AC turning on and off, right?

Ed...please describe how much RPM drop off you are getting. Thanks
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Old 05-30-2006, 02:03 PM   #8
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Quote:
Originally Posted by willwren
Quote:
Originally Posted by McGrath
My boost gauge reads -10 at idle and doesn't move
Big one there. The Series 1 L67'* only got a MAP sensor if they had a boost gauge (SSEi'* only). But the Series 2 uses it for a boost reading AND PCM feedback. It'* a critical sensor used to determine engine timing advance and other important crap.

You either have a disconnected, faulty, or leaky sensor, or your boost is constantly in bypass.
Sorry I think I explained that wrong the gauge doesn't move at idle but when I'm driving it moves accordingly.

Bill the rpms normaly drop about 500-600rpms and when they do drop it sounds like the motor wants to die for a split second. They always pick back up very quick but many times the rpms will drop from say 1'500 to about 900-1000 when I'm just coasting down the road. Anytime they drop and I touch the gas they pick right up, almost like I'm waking the motor up from the little nap it wants to take.
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Old 05-30-2006, 08:02 PM   #9
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I had to replace a MAF about a month ago. It was $100 (something) at Napa.

My car would not idle, the RPM would get down almost to the bottom, and the car would die if I didn't hit the gas. The check engine light came on as soon as the problem started. I replaced the part, and didn't have the problem anymore.

I have a 99 SE
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Old 05-31-2006, 12:04 AM   #10
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Quote:
Originally Posted by vanalan78
I had to replace a MAF about a month ago. It was $100 (something) at Napa.

My car would not idle, the RPM would get down almost to the bottom, and the car would die if I didn't hit the gas. The check engine light came on as soon as the problem started. I replaced the part, and didn't have the problem anymore.

I have a 99 SE
Makes me think the problem first showed up my CEL came on but I was on a long cruise and didn't know where any Autozones or anywhere I could get a quick scan. But the light went off soon after. Oddly enough that same cruise I got the best mileage I'd seen in my SSEi 32-33mpg.

Someone please suggest something else to check; thanks.

Ed
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