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MAF trouble?

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Old Oct 19, 2003 | 02:04 AM
  #1  
DannyT's Avatar
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From: Sacramento, CA
Car: 89 Iroc
Engine: 383
Transmission: 700R4
Axle/Gears: 3.45
MAF trouble?

According to my Auto X-Ray my MAF is reading 11776gr/sec when the car isn't even running. Is this a sure sign it is bad? Or maybe there is some buildup on the element? I get an occasional code 33 and changed the relays a while back. Usually when the code comes up I get a lot of hesitation almost like a fuel problem. This is a stock replacement MAF that I have had for several years with the screens removed.
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Old Oct 19, 2003 | 09:01 AM
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What are the gm/sec with the car running?
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Old Oct 19, 2003 | 06:08 PM
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From: Sacramento, CA
Car: 89 Iroc
Engine: 383
Transmission: 700R4
Axle/Gears: 3.45
LOL, I guess I should have checked that before but at the time I was only looking for SES codes.
At about 2000RPMs it reads in the 6000 gr/sec range and at 3800RPMs it is in the 12000 gr/sec range.
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Old Oct 19, 2003 | 06:19 PM
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Originally posted by DannyT
LOL, I guess I should have checked that before but at the time I was only looking for SES codes.
At about 2000RPMs it reads in the 6000 gr/sec range and at 3800RPMs it is in the 12000 gr/sec range.
I do believe that is waaaayyyy too high, Idle is 9-12 grm/sec
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Old Oct 19, 2003 | 06:29 PM
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From: Sacramento, CA
Car: 89 Iroc
Engine: 383
Transmission: 700R4
Axle/Gears: 3.45
Hmm, well I know I need to turn my idle down but without the proper chip I have to keep the FP high for performance. I rechecked the scan and the lowest reading was 2851 gr/sec at 1100 RPMs. I have a 58mm TB (among many other mods) if that matters.
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Old Oct 19, 2003 | 09:34 PM
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MAF = Kaplooie, time for a new one.
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Old Oct 20, 2003 | 11:05 AM
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8Mike9's Avatar
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From: Oakdale, Ca
Car: 89 IrocZ
Engine: L98-ish
Transmission: 700R4
Danny,

Disconnect the electrical connector at the MAF, turn the key on and now look at the MAF reading, it should default to 255gr/sec...if still reading those wild-high numbers, could be scanner or ECM issue.
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Old Oct 20, 2003 | 01:20 PM
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I wouldnt trust that Autoxray if I were you. Find someone with a different scanner, see what it says then. That and, it wont read 0 with the key on engine off anyway, I forget what they do read but its not 0.
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Old Oct 20, 2003 | 08:07 PM
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From: Sacramento, CA
Car: 89 Iroc
Engine: 383
Transmission: 700R4
Axle/Gears: 3.45
Originally posted by 8Mike9
Danny,

Disconnect the electrical connector at the MAF, turn the key on and now look at the MAF reading, it should default to 255gr/sec...if still reading those wild-high numbers, could be scanner or ECM issue.
I'll try that. I didn't know that 255gr/sec was the default, thanks.
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Old Oct 20, 2003 | 09:05 PM
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From: Sacramento, CA
Car: 89 Iroc
Engine: 383
Transmission: 700R4
Axle/Gears: 3.45
Originally posted by madmax
I wouldnt trust that Autoxray if I were you. Find someone with a different scanner, see what it says then. That and, it wont read 0 with the key on engine off anyway, I forget what they do read but its not 0.
Hopefully you are right. I unplugged the MAF and scanned it while running and it was reading 3228 gr/sec. The same with the sensor unplugged and the key ON but not running.
Can anyone else confirm what their MAF values are when it is disconnected?
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Old Oct 21, 2003 | 05:49 PM
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From: Oakdale, Ca
Car: 89 IrocZ
Engine: L98-ish
Transmission: 700R4
As I mentioned before, with the MAF uplugged and key on, mine read 255...using my SnapOn scanner.

Maybe someone else will be able to verify as well.
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