MAF advice - Page 3

azaytsev · 18th January 2008, 19:37

Quote:

Originally Posted by Stack

Thanks for the input. My car runs fine and pulls really hard but since I never had one before I wouldn't' know if anything is wrong. Of course I have had the car checked out and it was given a 2 thumbs up by the dealership as to the health of the car.

The same here, never driven one before...put new MAFs expecting more power...and found out my sensors were fine (even thou numbers were low)

gsfent · 18th January 2008, 23:59

Quote:

Originally Posted by THRILOS5

the L/H test is not very accurate because you can calibrate the OBC to give you any readings you want, I think is test # 20, I posted this in another thread, so some cars can have higher #'s than others but lower MPG readings since both the L/H and MPG work off the same sensor/calibration

Is there some source for that? I am not aware that they are tied together, but even if so, the adjustment for fuel mileage is so small, I don't think it would even show up on the L/H test. The base number is 1000 and goes up to I think 1200 and down to 800. Mine is set at something like 1010 to get accurate fuel mileage numbers.

Quote:

also the VW MAFS tend to run 4% richer hence the higher L/H numbers right away, you might notice a litle more responsiveness when you first put them in, but at idle and WOT they tend to run on the rich side, more noticable during the summer heat,
thats not good for your plugs also piston washdown and a rich condition would atribute greatly to a carbon build up problems

I thought that while there is a 4% difference, someone pointed out that the car's adaptation would compensate so that after a few miles of running the car would not be able to tell the difference.

Quote:

I would either stick with the oem MAFS or I would look for the same alternate replacement with a better price

One option, but lots of board members have had good luck with the VW MAF's. Now if we could get someone from Bosch to make the 029's available, I think we could sell a bunch right here, even if more $$ than the 032's.

Regards,
Jerry

THRILOS5 · 19th January 2008, 01:58

Jerry,
you know from my other posts that I test my car everytime that I change something since I like my car to run 110% and it does, I wasn't happy with the VW mafs, it was like some ooomph was missing from my car, I took it to the track and my mph was down by 3-4mph also when I did some rolls with my cousins e46 m3 from 50mph in third gear I had a hard time pulling on him(dead even up to 100mph)
I switch back to my oem mafs my mph went up by 3-4mph at the track and I started pulling on the m3 from 80 on, also the overich condition was gonne,
the cars DME can correct some of the fuel adaptations but it still on the rich side with the VW mafs

guys this only my opinion and personal experience, other cars may vary

Harry

THRILOS5 · 19th January 2008, 02:00

I think member London Mike had a source for the bosch 029 mafs from England, search his threads

mottati · 19th January 2008, 02:08

have you guys checked your coolant temp? My car was running a bit sluggish, went to test 7 in the obc and found my car was consistantly running between 75 and 79C. (actually ran the test because the temp gauge seemed a little more to the left than usual).
Thermostat wasn't fully closing. Had it replaced, now runing 80+ and car is running much better. Car doesn't go into closed loop until temp is 80C. Just something else to watch.

azaytsev · 19th January 2008, 02:10

Quote:

Originally Posted by THRILOS5

I think member London Mike had a source for the bosch 029 mafs from England, search his threads

for that price you can buy them here

THRILOS5 · 19th January 2008, 04:58

Quote:

Originally Posted by azaytsev

for that price you can buy them here

you're right

richie_rvf · 21st January 2008, 12:15

Quote:

Originally Posted by Stack

How do you adjust for altitude and weather? I live in Houston which is basically sea level, and it was about 50 degrees outside.

Sorry for the delay.....

How to test the MAFs yourself and How MAFs work

Toward the end of the first post there is an attached excel spread sheet.

Richie.