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Old Jan 22, 2009 | 09:01 AM
  #1  
badblackiroc's Avatar
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From: boomer, nc
Car: 88 IROC-Z
Engine: L98 350 Built
Transmission: Built 700R4
Axle/Gears: 2.73
MAF Question

I think my MAF sensor bit the dust, is there anyway to test the MAF or what relays do i need to check to make sure its doing what its supposed to.
what its doing is i can start my camaro and it will run for about 3 seconds and turn off.
and i go unplug the MAF and it runs fine, so to speak. im about 100% sure its the MAF.
so anybody with any other suggestions before i go and buy a new maff, would be great.
thanks, Joseph
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Old Jan 22, 2009 | 10:29 PM
  #2  
birdtojag's Avatar
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From: Mesa AZ
Car: 87 Firebird, 90 bird coming soon
Engine: 355 Chevy Vortec Heads TPI, LT1 inj
Transmission: 700r4
Axle/Gears: 2.77 posi 9-bolt
Re: MAF Question

You found the issue. MAF sensors go bad and to find out if it's that or something else, you unplug it. If runs better, MAF is bad.
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Old Jan 23, 2009 | 07:35 AM
  #3  
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From: Southern IL
Car: 88 GTA "Cocaine"
Engine: 350 tpi
Transmission: 700r4
Axle/Gears: 3.27
Re: MAF Question

also make sure that the connection to the mafs is good

while it is running move the connector around and see if it smoothes out
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Old Jan 23, 2009 | 03:40 PM
  #4  
Russ-So Cal's Avatar
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From: Lakewood, ca. USA
Re: MAF Question

I have speed density, so I'm certainly not an expert, but before you condemn the maf, could a bad burn off relay cause the same problem?
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Old Jan 23, 2009 | 04:29 PM
  #5  
BC GTA's Avatar
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From: Victoria, British Columbia
Car: 1989 GTA
Engine: 5.0 TPI
Transmission: T-5 WC
Axle/Gears: Yukon 3.73
Re: MAF Question

From what I have read and observed my mechanic do preform the tap test. Gently tap the MAF sensor and, if while the engine is running, the engine responds differently then the MAF sensor is faulty.
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Old Jan 24, 2009 | 03:52 PM
  #6  
badblackiroc's Avatar
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From: boomer, nc
Car: 88 IROC-Z
Engine: L98 350 Built
Transmission: Built 700R4
Axle/Gears: 2.73
Re: MAF Question

the car wont run at all if its plugged in, and correct me if im wrong but a burn off relay is so when crap clogs up the maf the burn off relay turns on a heating element to "burn off" the crap right? if i plug the sensor in and start the engine it runs for 3 seconds and and turns off, if i unplug it it runs fine so to speak, and it doesnt turn off, and doesnt the maf also run to the oil pressure safty switch for the fuel pump as well so it would cause the pump to starve the engine of fuel to turn off if its bad?
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Old Jan 25, 2009 | 06:03 AM
  #7  
rgarcia63's Avatar
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From: Houston, Texas
Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Re: MAF Question

Originally Posted by badblackiroc
...doesnt the maf also run to the oil pressure safty switch for the fuel pump as well so it would cause the pump to starve the engine of fuel to turn off if its bad?

A "Hot at all times" fuse powers both the OPS - Oil Pressure Switch and FPR - Fuel Pump Relay which are in parallel with each other and power the MAF & Fuel pump. An open OPS will interupt power to the fuel pump & MAF only if the relay also fails open. Even if there's no problem with the above circuit the ECM can disable the fuel pump if it doesn't receive a distributor reference signal.

FYI - The fuel pump circuit you described did exist at one time. Now it's design to insure power to the pump, not turn it off.
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Old Jan 25, 2009 | 06:31 AM
  #8  
VAN454's Avatar
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Posts: 330
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From: Melbourne Australia
Car: 88 GTA
Engine: Ls1
Transmission: 4L60E
Axle/Gears: 9 bolt 3.27
Re: MAF Question

I have the same issue atm, but it is intermitant I believe it is the MAF on my car too. I am considering the micro-tech non adjustable unit. Is this a good way to go? Anyone know where I can order one online?
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Old Jan 25, 2009 | 09:58 AM
  #9  
rhead007's Avatar
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Joined: Jan 2004
Posts: 75
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From: chicagoland
Car: 73LT,81Z,85Z
Engine: 350 350 350
Transmission: 700r4 700r4 700r4
Re: MAF Question

id like to know the wire scematic so i could jump it out into closed mode sure itll run crappy cold but thats better than all the time anyone got the scematic on these ???
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Old Jan 25, 2009 | 06:30 PM
  #10  
badblackiroc's Avatar
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From: boomer, nc
Car: 88 IROC-Z
Engine: L98 350 Built
Transmission: Built 700R4
Axle/Gears: 2.73
Re: MAF Question

i just put in a new distributor, and i tested it and its putting out a signal, the only thing i can see thats a problem is the MAF. both the burn off relay and the the power relay for the MAF tested out fine and i thought that wouldent be a cause since i replaced them in feb of '08. i figured id go and replace the major relays since i was putting in a fresh engine.
plus the MAF thats in it the guy that had it before me cut out the honeycomb filter screen in the MAF so that could be a factor in the MAF dying or being bad.
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Old Jan 27, 2009 | 06:33 PM
  #11  
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From: Southern IL
Car: 88 GTA "Cocaine"
Engine: 350 tpi
Transmission: 700r4
Axle/Gears: 3.27
Re: MAF Question

buy a helms manual
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Old Jan 27, 2009 | 09:05 PM
  #12  
rgarcia63's Avatar
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Joined: Jan 2003
Posts: 2,133
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From: Houston, Texas
Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Re: MAF Question

Originally Posted by jamon8
buy a helms manual
I have an account with ALLData, No offense, Helms manuals blow AFAIC.
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Old Jan 31, 2009 | 07:18 AM
  #13  
jamon8's Avatar
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From: Southern IL
Car: 88 GTA "Cocaine"
Engine: 350 tpi
Transmission: 700r4
Axle/Gears: 3.27
Re: MAF Question

no offense taken

its kind of a standard answer for me

I am glad you have some diagnostic tools at your disposal
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Old Jan 31, 2009 | 08:45 AM
  #14  
64deux's Avatar
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Joined: May 2008
Posts: 28
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From: southeast
Car: GM WHAT ELSE IS THERE
Engine: 327 bottom tpi top
Transmission: 700r
Re: MAF Question

tell me what you are working and i will post the diagram
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Old Jan 31, 2009 | 10:52 PM
  #15  
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From: south Louisiana
Car: 1985 Z28
Engine: 85 L98
Transmission: 700r4
Axle/Gears: stock 10 bolt-3.73 eaten posi
Re: MAF Question

unpluging it won't tell you if it is bad or not.
are you getting any trouble codes??
look inside the MAF and see if any of the wires are broken, that happened to me.

i think i have an extra MAF if you need one too.

here is a wiring diagram; http://www.austinthirdgen.org/mkport...ine_wiring.gif

Last edited by 3rdgenZ; Jan 31, 2009 at 10:55 PM.
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Old Feb 1, 2009 | 11:46 AM
  #16  
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Re: MAF Question

Umm, the MAF analog, so you can actually measure the output signal voltage from the MAF to see if it is bad or not. While you're poking around there with your voltmeter, make sure the input voltages are ALL present and that the burn-off signal is NOT present.
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Old Feb 1, 2009 | 12:58 PM
  #17  
badblackiroc's Avatar
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From: boomer, nc
Car: 88 IROC-Z
Engine: L98 350 Built
Transmission: Built 700R4
Axle/Gears: 2.73
Re: MAF Question

i have a GM 88 camaro Manual, i have the diagrams and i was just looking for other ideas, and it says to unplug the maf after testing several things and it said if the problem resolved itself after unpluging the maf that it needed to get replaced
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Old Feb 1, 2009 | 03:32 PM
  #18  
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Re: MAF Question

...Unless the burnoff relay is applying power to the MAF terminal "E" in which case the MAF will erroneoulsy report a full 5.0 VDC signal.
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