Air filter is new. Cleaning the MAF is a good idea but I've heard that the problem usually comes back if only a cleaning is done. I'm doing this for someone and don't want them coming back in a few weeks with same complaint. Have you had experience with cleaning and lasting results. Do you clean with aerosol, such as brake cleaner or do you use a swab and alcohol?

__________________
1972 450SL
1982 300D Turbo

I use CRC MAF cleaner ..aerosol.
Works great and fast/easy to use..

I cleaned the MAF with CRC electrical contact cleaner which is the same formulation as CRC's MAF cleaner. Results were negative. I then tried cleaning it with alcohol on a swab and got modest to no improvement. I replaced the MAF with a new Bosch unit and car is fixed! I'm measuring about 550kg/hr at 4000 RPM, 3rd gear WOT. This is what it should be.

btw, I've "fixed" a few Toyotas throwing lean codes by spraying the MAF but doesn't seem to work as well with these MB Bosch film type MAFs, at least in my limited sample group.

__________________
1972 450SL
1982 300D Turbo

Same here . . in the three or so 'film' type that I've done, they didn't "stay" fixed but cleaning the older hot wire type works perfectly.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

I know this is an old thread but I am having an odd issue and want to rule my MAF out as a cause. I have a 02 E55 and I am getting -18% fuel trims (less then 1% difference left to right) with my new MAF module.

I have post my original question in this thread but I am not getting any answers

http://www.peachparts.com/shopforum/showthread.php?t=210103

Thanks

__________________
Eraser-X
06 R350 with sport package
02 E55 Black on Black with most options
91 Range Rover GDE
8X 280TE
53 356 Cab

Attach your OBDII scanner and read the air mass flow measurements generated by the sensor at WOT in 3rd gear and at 4000 RPM. You'll have to shift the car into 3rd. You have to catch your reading at 4000RPM so you may want a helper to read the scanner just when you hit 4000RPM so that you can remain concentrated on the road while accelerating on the highway. You want to see a MAF reading that is about 550kg/hr or more. Convert 550kg/hr as needed to match your OBDII scanner's mass flow units. For example multiply 550 by 2.2 and divide by 3600 to get it into lbs/sec. That's all the help I can give you.

BTW, don't do this during rush hour! you need an open highway.

Just realized you have a different car so you need to get the spec for your engine. Any MB tech with access to MB specs should be able to give you this. I have a friend at the dealership who gave me this for the car I was working on.

__________________
1972 450SL
1982 300D Turbo

Sorry to threadjack, but are you saying a standard OBDII scanner will give MAF readings? I don't recall reading that in my scanner's manual. I thought only SDS could provide adaptation values and you had to use a multimeter in conjunction with MAF manufacturer documentation?

__________________
08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280