How can i know if my MAF sensor is functioning properly? when i unplug it the idle goes crazy jumping all over the place, but that is not a sufficient indication that it is working correctly, or is it?

Thanks,

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1993 300E, 2.8 M104 .....

No it is not.

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Gone to the dark side

- Jeff

Thanks, what would be a proper test?

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1993 300E, 2.8 M104 .....

Here is a document on testing MAF's.

Attached Files

BoschAMM-Spec_Testing.pdf (157.3 KB, 275 views)

That is a cool document but I am not sure how I would use it as a test procedure. To the OP: why do you want to test it?

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Does your car have a hot wire MAF, or just an airflow meter with a flapper plate?

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Slow response, slight idle irregularity, gas milage not great, you have to hit the gas hard to get it going ...

wires, head-gasket, O2, cam position sensor, sparks are all new, ...not much more tuning to do on this engine? or am i missing something....

My engine has the HFM system, with the Bosch MAP sensor similar to No. 2 in the document, but with a round plug...

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1993 300E, 2.8 M104 .....

Here is a thread that might help. I searched on "300E MAF", lots of hits.

http://www.peachparts.com/shopforum/showthread.php?t=222222

You might build or buy a code reader for that and see if there are codes.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Yes code reader is the place to start, in addition to code reader you need live data which will give lot of info on how your car is running. I have been using free HFM scanner
(http://www.peachparts.com//shopforum/showthread.php?t=236925) for my M111 and it has been handy software to have.

HFM ECU's are not very sensitive, you usually won't see a error code's for rough idle, minor air leaks etc.

300E does not have a MAF sensor.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

This is a 300e 2.8 with the HFM engine management system..why do you say there in no MAP sensor?

Thanks

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1993 300E, 2.8 M104 .....