Hi!

The mass air flow sensor in my car doesn't seem to work at all. I can unplug/insert it while the engine is running with no effect what so ever, so I thought I'd test it or maybe clean it. I tried googling for information, only to discover that there is very little available on the type of MAF that I've got in my car.
The car is a 1994 850 stationwagon with a 2.5 non-turbo 10-valve (144 horsepower).

Mine is the size of a thumb and has a blue socket with a black casing coming out of it, housing the sensor wires. The sensor seems to be 2 connected wires with tiny knobs on their ends. The blue socket says Siemens on it, and if I remember correctly there's two numbers on it - "131-5" and "1537-1".
There are only two wires attached to it (which probably means that it doesn't have an "onboard" temperature sensor, right?). The sensor is located on the accordian type hose that connects to the air filter box.

I would really appreciate as much information on this sensor as possible:
- cleaning
- testing
- theory of operation
- voltages

Oh and by the way I've checked the voltages on the 2 wires that connect to the sensor. Putting a voltmeter between them displays 5.0 Volts with ignition on, engine not running.
Is this right?

I'd really hate to buy a new one, since it costs NOK 4500,- at my dealership here in Norway. That's roughly $900,- USD, and clearly completely insane!

Cleaning would be the same, irregardless of whether its for the R or non-turbo. Either you can get an aerosol can that says "AirFlow Sensor Cleaner" like what you see on CRC products, OR you can use Contact Cleaners of the aerosol type and clean the maf sensor head GOOD.

Good day, Ampang!

I'm glad you responded, but I was in fact about to delete the post since it turns out that I have made a little mistake :grin:

It turns out that the sensor on my car that I described in the initial post is in fact something as unexciting as an Intake Air Temperature sensor.
Since my car is a 1994 with the Fenix 5.2 system it doesn't have a MAF sensor.
Instead it uses a MAP (Manifold Absolute Pressure) sensor combined with said air temperature sensor to figure out the air mass.

However I would still like some input on this sensor.
I haven't gotten any error / fault codes for it, but my car is running so slow there must be something wrong somewhere.

Would a faulty MAP sensor produce a CEL?

Thanks again!

Hey, no worries, sir.

And Yes, it would. The IAT is at the bottom of the air hose from the aircleaner/filter box. The IAT is also connected to the fame trap hose.

I normally just cleaned it, especially if and when it gets dirty with oil residues when blow-by gas passes through. Blow-by gas is gas that is from the combustion chamber as a result of the explosion and firing of the engine.

But eversince i bypassed the system, i have left the top hose unconnected. I'll cap it soon. It's sending additional and unmeasure air into the combustion. Hehe.



You can clean it with petrol / gas.

Ok I think I'll clean it even though I was really looking for the MAP :)
It won't make it any worse than it is anyways.

Good luck!
:)