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How to test a MAF
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Old 25 Aug 2007, 06:19 AM   #1 (permalink)
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How to test a MAF

Im new to thi site and to the impreza world so bear with me

I'v got a 1996 impreza and from what i'v read in a few articles, my car has got the MAF flu!

How would i test this myself? If i unplug it should it die or keep running?

Thanks for any help!!!!
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Old 25 Aug 2007, 07:02 AM   #2 (permalink)
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Unplug the MAF whilst the car is up to temp and engine running. If the MAF is doing its job then it should misfire - cough splutter etc - however if the car continues to idle fine your MAF has the flu.
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Old 25 Aug 2007, 07:46 AM   #3 (permalink)
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Thanks for the info,

I had my car engine washed about two weeks ago by my mechanic, who is generally very good with Subaru's. but my car hasn't been the same since!! its got an eratic idle. if i come to a stop, the revs drop to 100-200 rpm and then shoots up back to normal. but it does this continuasly untill i tap the acc. pedel.

this is why i think the maf could be at play. I it really wise to even attempt to clean it? and if it is, i can only fine switch cleaner here. will it work?


thanks again.

Last edited by NatWrex; 25 Aug 2007 at 07:48 AM.
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Old 25 Aug 2007, 09:27 AM   #4 (permalink)
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I had my car engine washed about two weeks ago by my mechanic, who is generally very good with Subaru's. but my car hasn't been the same since!!


I don't think you can clean the MAF. Just unplug to the sensor, it could settle it down.

Have a look at this thread.

http://www.subaru-impreza.org/bbs/sh...ad.php?t=14449
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Old 27 Aug 2007, 05:13 AM   #5 (permalink)
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Well, i did the unplug and the car died very quickly. No coughing or spluttering???
I take it this is a good sign and it makes me wonder if i didn't get a batch of bad fuel?
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Old 27 Aug 2007, 07:16 AM   #6 (permalink)
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If your engine died it's not the MAF.
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Old 27 Aug 2007, 08:02 AM   #7 (permalink)
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Originally Posted by NatWrex View Post
Thanks for the info,

I had my car engine washed about two weeks ago by my mechanic,

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Quote:

if i come to a stop, the revs drop to 100-200 rpm and then shoots up back to normal. but it does this continuasly untill i tap the acc. pedel.
Have a look at the accelerater cable on the throttle body, it could be dry.
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Old 27 Aug 2007, 08:16 AM   #8 (permalink)
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Some ppl have got away with cleaning the maf sensor however when i did mine car were running crap beforehand and got to the point where it`d cut out on tickover-cleaned maf then it decided to throw a faultcode, didnt before i`d cleaned it put new maf sensor on an it were fine.

(i wouldnt recommend getting loads of water round an imprezas engine bay anyway too many sensors etc to upset-when i do mine use aerosol precision cleaner/brake cleaner/ autoglym engine and machine cleaner a wheel brush or paintbrush to agitate the stubborn stuff and to get at the awkward bits then just a hosepipe/watering can so youve more control over where the waters going over using a pressure washer - the waters not being forced anywhere then. )
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Old 06 May 2010, 08:01 AM   #9 (permalink)
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Re: How to test a MAF

CRC make MAF cleaner, you just spray it on the hot wires, 5 minute job in most cases but also costs $22 a can....Seems to work though.

My car is a rally car so the engine bay is regularly cleaned with high pressure water and soap and it is always fine. One obvious thing, if you have a POD filter then take a shopping bag and 2 cable ties. I also have a photo where most of the car is hidden behind a 20ft rooster of water, you can see it being forced out near the bumper indicators and the car was still fine. Despite all the sensors they don't seem to mind a bit of water.

Cheers

Jade
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Old 21 May 2010, 12:29 AM   #10 (permalink)
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Re: How to test a MAF

I WASHED MINE IN BRAKE CLUTCH CLEANER WORKED A TREAT CHECK THIS OUT FOR PROPER MAFF CHECK
Testing Sensors
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Old 22 May 2010, 03:27 AM   #11 (permalink)
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Thumbs up Re: How to test a MAF

Hi,

Be a little bit careful what you clean the MAF sensor with there are warnings posted everywhere. Mind you they may just be trying to sell $22 worth of contact cleaner in a can too.

The link you left is unreal. That is the sort of thing I have been looking for and been unable to find out. How do we make sure anyone that needs to test WRX sensors can find it?

Cheers
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Old 22 May 2010, 03:31 AM   #12 (permalink)
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Re: How to test a MAF

Oh, one other thing. This only applies if you have an air cleaner that requires oiling. If you put too much oil on the filter it can go through to the MAF and trigger a fault code (23 from memory). Cleaning it gets rid of it.

The problem in my line of fun is, too little oil on the filter and the MAF gets covered in dust along with the rest of the intake, too much and you get a fault.

Cheers.
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