How to test mass air

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Dec 5, 2007 | 11:46 AM
  #1  
89 tpi 350 is running very very rich, im testing sensors, the tps was off so I adjusted it to .5 at zero throttle, next I went to the maf and im not sure how to test, and also it has a crack where the inner tube connects to the rest to the unit. so I need some solid test procedures and them opinion on the crack.
one more thing, I need a how to to test o2 sensors. thanks.
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Dec 5, 2007 | 12:07 PM
  #2  
Re: How to test mass air
I've been wondering the same thing. I've got a spare MAF, and believe it to be good, but I wanna KNOW if it is good or not.
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Dec 5, 2007 | 07:18 PM
  #3  
Re: How to test mass air
no one knows??? Its just a mater of which wire is hot, which one is ref. ect.(I just dont want to fry it but poking around and hopping) So you all just replace them and hope your $200 guess was the right one??
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Dec 5, 2007 | 07:46 PM
  #4  
Re: How to test mass air
I'll ask my OPEG, It hasn't been a priority for me, so I haven't bothered to ask him.
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Dec 5, 2007 | 08:20 PM
  #5  
Re: How to test mass air
thanks, that would be great, I've got too limited of a budget to just guess
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Dec 5, 2007 | 09:05 PM
  #6  
Re: How to test mass air
you need a profressional scope, very expensive. most good shops have them
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Dec 6, 2007 | 10:20 AM
  #7  
Re: How to test mass air
OPEG says jayk2k3 is right. No easy/cheap/un-complicated way to test a MAF.

If you've got a MAF buddy, swap MAFs with him, to test & eliminate it.
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Dec 6, 2007 | 10:30 AM
  #8  
Re: How to test mass air
OPEG here.

This thread has some answers but beware, the tests are nothing but simple "does-it-even-work" tests. They won't tell you how precise the MAF output is, they'll just tell you if it works or not.

https://www.thirdgen.org/forums/v6/3...-test-maf.html

If you have some local 3rdgen buddies, you can borrow a MAF from them for 5 minutes and see if that fixes your problem. If not, it's not likely the MAF.

On a side note, a rich running condition can be caused by multiple factors. The CTS may be disonnected (bad wiring) or read maybe -20F, the injectors might be flowing at different rates (been there), the IAT may be reading way low too ... as I said, multiple factors. It would help to hookup a laptop to it to see what the ECM sees and does.

Hope this helps.
Lou
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Dec 6, 2007 | 03:20 PM
  #9  
Re: How to test mass air
Thanks, this helps, and Ive checked all the other stuff, this was just the last thing, im a test first kinda guy. maf is bad btw
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Dec 7, 2007 | 12:26 PM
  #10  
Re: How to test mass air
A DMM (anything with voltage and a frequency counter) and a typical MAF table off the 'net can be used to diagnose just about all of GMs MAFs. Typically at idle you should see around 6-8 grams per second of airflow for a V8.
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Dec 9, 2007 | 12:25 AM
  #11  
Re: How to test mass air
Quote: A DMM (anything with voltage and a frequency counter) and a typical MAF table off the 'net can be used to diagnose just about all of GMs MAFs. Typically at idle you should see around 6-8 grams per second of airflow for a V8.
And we count grams per second how....at home?
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Dec 10, 2007 | 08:52 AM
  #12  
Re: How to test mass air
Quote: And we count grams per second how....at home?
You would use those MAF tables off the internet (mentioned above) and calculate what airflow specific voltage translates to.

Lou
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