L98 MAF Sensor Testing?
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
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From: Herriman UT
L98 MAF Sensor Testing?
Is there any way to test the MAF Sensor? I purched the "test tool" from MAD that plugs into the harness at the sensor & allows you to measure voltage at each lead with the engine runnning. No instructions were provided on what the readings should be. Can anyone advise?
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
Re: L98 MAF Sensor Testing? (vader86)
I havn't taken readings yet. I'm wondering if a bad MAF could have anything to do with the "lurching" problem I'm having. I you say, try and drive in 1st gaer at, say, 5 mph, the car begins lurching so bad you have to depress the clutch for it to stiop. It's always done it, prior to and after the new cam.
Le Mans Master
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Re: L98 MAF Sensor Testing? (geezel)
Sorry about it being a lil' dirty. I have used it before. :thumbs:
http://temp.corvetteforum.net/c4/joh...structions.jpg
[Modified by War Machine, 12:49 PM 2/26/2004]
http://temp.corvetteforum.net/c4/joh...structions.jpg
[Modified by War Machine, 12:49 PM 2/26/2004]
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
Re: L98 MAF Sensor Testing? (War Machine)
It looks like I need the following for an '86 L98:
1 Location of ECM connector from the MAF (Refer to GM shop manual).
2 Voltage equirements for each MAS pin (Refer to GM shop manual).
Can anyone provide this information?
1 Location of ECM connector from the MAF (Refer to GM shop manual).
2 Voltage equirements for each MAS pin (Refer to GM shop manual).
Can anyone provide this information?
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Re: L98 MAF Sensor Testing? (geezel)
Stand on the passenger side of the car, right under the MAF you'll see the connector.
Voltages will take a bit because I'll have to track down my Shop Manual.
Jake
Voltages will take a bit because I'll have to track down my Shop Manual.
Jake
Race Director
Joined: Feb 2004
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Re: L98 MAF Sensor Testing? (JAKE)
One quick test for maf is the screwdriver handle test. With engine running give maf a decent couple of shots with the handle. If engine sputters and/or stalls its bad for sure. This caveman test will not prove that the sensor is good though. :smash:
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Melting Slicks
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From: St. Charles, MO Route 66 Corvette Club
Re: L98 MAF Sensor Testing? (War Machine)
I have a "clean & readable" copy of the MAD test device that I can send to you as a jpeg file. Using my "limited" recall, I do not believe the MAD instructions give you the good vs bad readings. Send me your email address if you want the copy.
SAM
[Modified by Sam Lam, 6:41 PM 2/26/2004]
SAM
[Modified by Sam Lam, 6:41 PM 2/26/2004]
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Re: L98 MAF Sensor Testing? (geezel)
:cheers: I don't think the MAF is the answer to "lurching"
I have recently had a lot of experience with the MAF :rolleyes:
MAF controls fuel air mixture! Engine will run lean or rich with malfunctioning MAF and will run base timing "limp home" with no MAF
Yes the MAF can switch from lean to rich and back pretty quickly, but probably not quickly enough to produce "lurching"
Sounds to me like a rapid on and off of fuel or ignition...curiously, the MAF relays (not the sensor) are wired into the fuel pump systemthrough the ground circuitry (don't ask me how, but the book says so)
I had MAF relays going bad and I got a rapid on/off of the fuel pump, which caused momentary engine cut out, but not "lurching"
Do you have a shop manual? I was fortunate enough to find a scan tool from a fellow Forum member and that saved me a lot of time.
:seeya
:steering:
PS I have the test tool you mentioned and I didn't use it because it seemed like the connections were touching each other and would be too easy to short each other out
[Modified by jackdaroofer, 7:52 PM 2/26/2004]
I have recently had a lot of experience with the MAF :rolleyes:
MAF controls fuel air mixture! Engine will run lean or rich with malfunctioning MAF and will run base timing "limp home" with no MAF
Yes the MAF can switch from lean to rich and back pretty quickly, but probably not quickly enough to produce "lurching"
Sounds to me like a rapid on and off of fuel or ignition...curiously, the MAF relays (not the sensor) are wired into the fuel pump systemthrough the ground circuitry (don't ask me how, but the book says so)
I had MAF relays going bad and I got a rapid on/off of the fuel pump, which caused momentary engine cut out, but not "lurching"
Do you have a shop manual? I was fortunate enough to find a scan tool from a fellow Forum member and that saved me a lot of time.
:seeya
:steering:
PS I have the test tool you mentioned and I didn't use it because it seemed like the connections were touching each other and would be too easy to short each other out
[Modified by jackdaroofer, 7:52 PM 2/26/2004]
