MAF Sensor test - really true?

[birgerfromvictoria]

The cel came on again today and the engine stalled at a traffic light. Too bad. I checked far vacuum leaks again but didn't find anything. My friend the mechanic will take a look on the weekend and if he has no better ideas I'll get the new Maf.

[birgerfromvictoria]

Just a follow-up post. I met my mechanic friend and we checked for vacuum leaks but it all looks good. I also changed from midgrade to premium fuel and there's no stall or cel so far. Actually it runs like the devil right now (in a good way, yay!)

[birgerfromvictoria]

The car stalled again yesterday so I tried a new angle today and cleaned the throttle body. It looked pretty bad - maybe that brings some change. I've read that somewhere that this is associated with engine stalls when idling.

before cleaning

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after cleaning

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Let's see what happens now. Hope that solved the problem. Thanks for the great instructions concerning how the clean the TB.

[birgerfromvictoria]

Here's another follow-up:
Cleaning the throttle body stopped the stalling but instead the car started idling very roughly after a longer drive. The fuel mileage was also approx 10% better than before the cleaning.
When I let the car idle roughly for a while the CEL came on and gave me the P0103 and in addition to this also P0171 and P0243. I spend some more hours browsing and searching MVS and came to the conclusion that I really might have to change the MAF after all.
I ordered a OEM part #0280217107. When I installed it I also made sure to reset the computer by disconnecting the battery for some time.
Well, the result was pretty impressing. No rough idling at all anymore and the torque seem to be more balanced at any revs. The general performance of the car seems to be improved significantly. So much fun for under $200.00 bucks.

[boosted5cyl]

Sounds like you might be on a good path.

For the record, pulling the MAF to test while the motor running is a bogus test, and quite frankly a bad idea. You can disconnect the MAF THEN run the motor to see if things change for better or worse. Disconnecting the MAF while its running will often result in a stall, good or bad MAF, all depends on how the ECU takes to it.

You can monitor MAF readings for <$100 with a generic OBD cable.

[birgerfromvictoria]

Thanks for the advise. This is my first Volvo and my first turbo in general so I'm happy about your feedback.
Its been some days now since I changed the MAF and its still running great.

[JimBee]

You can also test your MAF with a multimeter (leads between power and ground). This page contains "how-to's".