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Old 11-23-2010, 06:43 AM   #1
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Default Possible failing MAF?

So yesterday Im out driving and I stop at a light. While there the engine just cuts off. I put it in park and restart, fires right back up. A little ways up the road, car started bucking. I was inclined to believe it was a tranny issue but that doesnt explain why the car cut off. I pulled over checked the tranny fluid, looked fine, proper level. Remember something i had read in one of the threads, tried tapping the MAF, what do you know, the engine began to shudder, almost cut off. Havent had it scanned yet supposed to do this later this afternoon. However based on the description what do you guys think? Also there is no SES light as of yet. Plan on unplugging the maf when i get home and seeing how it runs.
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Old 11-23-2010, 09:06 AM   #2
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If it stumbled when you tapped the MAF that'* a good indication the MAF is having issues. Unplug and drive. Remember to drive easy.
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Old 11-23-2010, 10:19 AM   #3
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So are these common symptoms of a MAF failure then?
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Old 11-23-2010, 10:25 AM   #4
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Yes, they can be, depends on how it fails. You tapped on it and it stumbled, same thing happens when driving. If that happens at the right time, then engine just stalls.
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Old 11-23-2010, 10:27 AM   #5
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makes sense. thanks Dan i'll keep u posted
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Old 11-23-2010, 12:01 PM   #6
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When you unplug the MAF, the car determines fueling based on the VE table. It goes into something called Speed Density mode. It won't run very well, but it will run. If it stays running better once you unplug it, you've found your problem.
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Old 11-23-2010, 01:02 PM   #7
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Quote:
Originally Posted by xtremerevolution View Post
When you unplug the MAF, the car determines fueling based on the VE table. It goes into something called Speed Density mode. It won't run very well, but it will run. If it stays running better once you unplug it, you've found your problem.
Intresting this Speed Density Mode!

I tryed somthing yesterday just fooling around ! I placed some ice on top the MAF when car stumbled, after that the car smoothed out and was ok, but the assume the position soon light was still on. It stays that way until I let the car cool completely. Maybe I by-passed something. If I restart the car the light is off and no troble codes found! Might be woth a try to zero in on the MAF problem, I havent tryed beating yet!
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Old 11-23-2010, 01:12 PM   #8
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Electronics don't like heat. The MAF is bad.
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Old 11-24-2010, 05:13 AM   #9
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SO this is how yesterday went. Got home, started the bonnie up, let it sit until engine got warm, was busy cleaning out my truck when i heard the engine almost die. popped the hood on the bonnie, tapped on the MAF, engine almost died again. QUick trip up the street to Advanced Auto parts, New MAF, (138.99) Installed it in the parking lot, followed by 30 min test drive. No more stalling, surging or bucking. Im calling this one fixed.
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Old 11-24-2010, 10:10 AM   #10
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Well done. When it comes to the MAF it'* something you want to test, test, and test again. The part is expensive and swapping it out only to find the problem is not fixed sucks. But in this case you did several tests, unplug, tap, and ice. All showed a bad MAF.
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