Testing MAF
#1
Testing MAF
So, I just tested my MAF and assuming I did it correctly, it's bad.
When I tested the resistance between E2 and Vs I got 212 which is within spec.
When I tested the resistance between E2 and Vc I got 001.2 and my buzzer went off which goes off if resistance is below 40 ohms
When I tested E2 and Vb I got 003.2 and also got the buzzer
Then, when I tested E2 to THA I got 2.9 which I am confused about all the ranges that could be in spec with.
Does it seem like I did this test correctly?
When I tested the resistance between E2 and Vs I got 212 which is within spec.
When I tested the resistance between E2 and Vc I got 001.2 and my buzzer went off which goes off if resistance is below 40 ohms
When I tested E2 and Vb I got 003.2 and also got the buzzer
Then, when I tested E2 to THA I got 2.9 which I am confused about all the ranges that could be in spec with.
Does it seem like I did this test correctly?
#2
E2 to THA has a range relative to ambient temperature. So, if you tested it around 68 d F, then you test number is OK.
You should retest the for the rest, just to make sure. This is a very
expensive part to have to replace!!
Generally, if the test numbers are out of spec, the ECU will get wrong data, and the injector pulse width will be off.
gNARLS.
You should retest the for the rest, just to make sure. This is a very
expensive part to have to replace!!
Generally, if the test numbers are out of spec, the ECU will get wrong data, and the injector pulse width will be off.
gNARLS.
I tested every one of em over and over just to make sure.
#4
#5
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VAF, AFM, VAFM...
Volume Air Flow
Air Flow Meter
Volume Air Flow Meter.
"what by any other name on our trucks would do the same."
~me.
However, a MAF is "Mass Air Flow" which is not on our trucks.
Volume Air Flow
Air Flow Meter
Volume Air Flow Meter.
"what by any other name on our trucks would do the same."
~me.
However, a MAF is "Mass Air Flow" which is not on our trucks.
Last edited by abecedarian; 12-28-2009 at 09:53 PM.
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#9
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If you find the unit is bad I recently had to replace mine and after a thorough search the best deal I got on a re-manufactured unit was at Advanced Auto--$125 with core exchange. Comes with 12 mo. warranty.
Initially I attempted to fix mine by cutting silicone seal, removing top and cleaning all contacts. Worked great for a day; about 70 miles. The following morning a backfire was associated with code "31" and on removing top again it looked like a cherry bomb had been detonated inside the MAF sensor.
Initially I attempted to fix mine by cutting silicone seal, removing top and cleaning all contacts. Worked great for a day; about 70 miles. The following morning a backfire was associated with code "31" and on removing top again it looked like a cherry bomb had been detonated inside the MAF sensor.
#10
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There is a big difference between the two, the AFM has a flapper door inside of it that is pushed open by the incomming air. The MAF uses a hot wire thats inside of it to measure air flow, so a MAF is an electrical part that measures air flow, were as the AFM used on our engines is more of a mechanicle part thats operated by air flow.
#11
IF the AFM is out of spec in any area at all its bad. But if your truck is running decent and don't have money to replace it then keep driving. Remember there are a few parts in that test to where you have to open and close the flapper door.
#13
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Everything you ever wanted to know about air flow sensors/meters.
http://www.autoshop101.com/
Go to TECHNICAL ARTICLES
then down to Toyota Series - Engine Performance OBD-II
then to 34 Sensors #4
http://www.autoshop101.com/
Go to TECHNICAL ARTICLES
then down to Toyota Series - Engine Performance OBD-II
then to 34 Sensors #4
#14
Sorry if I missed this, but how was it running before? Or was it not running? I'm wondering because after messing with my intake tube while I was changing my water pump and timing belt my truck won't start unless I unplug my VAFM (runs for 7 seconds before losing fuel pressure and dying).
#15
What are the exact specs for testing an actual MAF, not AFM, for my 2000 4Runner 3400 5VZ? I'm having problem with mine. Lousy instructions in the Chilton's book for my model gives me a test that is inconclusive. Don't want to replace an expensive working part.
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