LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

MAF sensor ground...Where is it?

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Old Nov 6, 2007 | 02:43 PM
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From: Sandy VJJville
MAF sensor ground...Where is it?

I'm trying to troubleshoot some problems I'm having with my car and I want to check the ground for the MAF sensor. I'd like to know where the harness for it grounds to on the car.
Old Nov 6, 2007 | 02:49 PM
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i duno where the ground is, but if you are having problems with the MAF most people find that it is the power wire shorting out. Happenes in ALOT of cars.
Old Nov 6, 2007 | 03:04 PM
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From: Sandy VJJville
Alright, I'll give the full history of this problem.

I have been getting the P0100 code for who knows how long now. I was having problems with the car stumbling and bucking every so often. Even at some points it seemed to be just in a certain RPM range. I tried a couple of my friends' MAF sensors and the SES light went out and the car ran fine (or at least it did on the ~5-10 minute test drive.) I've driven the car without the MAF sensor connected and I still have the same problems and the SES light is on. P0100 is the only code I've gotten this whole time.

I bought a MAF sensor from the dealer. I had the same problems as my old sensor. Swapped it for another and the same problem persisted. I tried my friend's again and the car was fine. I bought tried a brand new aftermarket MAF and it had the same problems. I bought another used one from a member here and the SES light is out but it's still running like crap.

So now I have the latest used sensor on there. The current status is that the SES light is out but it runs badly. It stumbles and hesitates VERY badly when I'm driving and when I slow down with the clutch in, the RPM's drop way low and the car feels like it wants to die. If I hold steady throttle pressure while it's stumbling, it will run rough, surge a little bit, run rough, then it will clear up momentarily and do it all again. This usually starts within a minute or two of me starting the car and driving.

I've tested the power to the pink wire and I'm getting 11.69 volts with the key in the on position. With the car running, I get 13.7 volts to the pink wire. This is using the harness ground wire as a ground point. I also sprayed brake cleaner around the air intake ducting and there was no surge in RPM so I'm pretty sure that's all airtight. What else should I be looking for?

Last edited by shock6906; Nov 6, 2007 at 03:28 PM.
Old Nov 6, 2007 | 03:56 PM
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I had the same problem, The short in my pink wire.
I could never "catch" it shorting out when i hooked up the volt meter to it. i could reset the computer have the meter hooked up and have someone start the car, i would stare at the meter and it wouldnt really move but 5 min later the ses light was back on

I just pulled the wire out of the pigtail and ran a new wire from my battery to the MAF, havnt had a problem since!

Try to splice into the wire as close to the conector as posable and run it to your battery, then unplug the battery for 5 min to rest the computer and see how that works for a few days.
Old Nov 6, 2007 | 04:17 PM
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Originally Posted by 97formula1234
I had the same problem, The short in my pink wire.
I could never "catch" it shorting out when i hooked up the volt meter to it. i could reset the computer have the meter hooked up and have someone start the car, i would stare at the meter and it wouldnt really move but 5 min later the ses light was back on

I just pulled the wire out of the pigtail and ran a new wire from my battery to the MAF, havnt had a problem since!

Try to splice into the wire as close to the conector as posable and run it to your battery, then unplug the battery for 5 min to rest the computer and see how that works for a few days.
How does the sensor not get power all the time if it is hooked up this way? Is there a switch from the computer?

I wound up getting a replacement pigtail off of ebay and putting it in. It is in the wiring though. I couldnt ever catch mine with a voltmeter either.
Old Nov 6, 2007 | 05:14 PM
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You probably need to take a drive with a scanner or data logging software hooked up. After educating yourself on what the readings mean, you should be able to more easily find the issue.
Old Nov 6, 2007 | 06:19 PM
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Where do I get access to one of these scanners/data loggers? I don't trust the car out in traffic at this point so I don't really want to drive it out of the neighborhood.
Old Nov 6, 2007 | 07:58 PM
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welp what i did was the ghetto way of fixing it/diagnoseing it but it did work.

if i was you i would this cheap fix to see if it works then go ahead and fix it the right way if it works
Old Nov 6, 2007 | 08:35 PM
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Originally Posted by shock6906
Where do I get access to one of these scanners/data loggers? I don't trust the car out in traffic at this point so I don't really want to drive it out of the neighborhood.
If you have a laptop you can get an ALDL cable and download Datamaster.
Old Nov 6, 2007 | 08:38 PM
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From: Sandy VJJville
Originally Posted by mdenz3
If you have a laptop you can get an ALDL cable and download Datamaster.
I don't have a laptop...
Old Nov 6, 2007 | 08:41 PM
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Originally Posted by shock6906
I don't have a laptop...
Well if you weren't at the far end of the state I'd let ya use mine.

Have any friends that work at a shop?
Old Nov 6, 2007 | 08:50 PM
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I know one guy, but I'm not sure if he has a laptop or whatever. He's got an OBDII scanner but I'm not sure if that would be of any benefit. I don't have an SES light on anymore.
Old Nov 6, 2007 | 09:32 PM
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Which car are we talking about the 93 or the 97? On the 97 a good scanner will be able to show the data inputs to the PCM in real time so you can identify when the issue is occuring and get a better idea of what is happening. The 93 would require a GM OBDI scanner.
Old Nov 6, 2007 | 09:51 PM
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Originally Posted by shock6906
Where do I get access to one of these scanners/data loggers? I don't trust the car out in traffic at this point so I don't really want to drive it out of the neighborhood.
Normally, people buy the tools they need. IMO, you can't really work on modern cars without a scanner, DVM, fuel pressure test gauge, some form of service manuals or reference and the right hand tools.
Old Nov 7, 2007 | 12:35 AM
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From: Sandy VJJville
Originally Posted by mdenz3
Which car are we talking about the 93 or the 97? On the 97 a good scanner will be able to show the data inputs to the PCM in real time so you can identify when the issue is occuring and get a better idea of what is happening. The 93 would require a GM OBDI scanner.
It's for the 97 Z.



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