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WickedFast.Inc 11-12-2012 01:24 PM

89 325i how do I correctly adjjust my afm

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Newman271 11-12-2012 02:31 PM

You have a air/fuel meter? Why do you think the afm is reading wrong?

Without knowing what your air fuel ratio is you really can't adjust it. I've read to just buy another one. I bought 3 from a junkyard for 5 bucks a peice.

WickedFast.Inc 11-12-2012 04:20 PM

Well is not bad but my idle valve is bad so the person before me **** with it so it would stay running at idle

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WickedFast.Inc 11-12-2012 04:21 PM

Air flow meter mass airflow meter before the intake my bad ive seen it wrote afm and mam

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BMWFatherFigure 11-12-2012 05:55 PM

I wood go mannyfold leeks bee forr I tried to ajust setting agin. (How is my Texas spelling?)

downhiller 11-12-2012 05:56 PM

just use the idle adjustment on the throttle body. afm/maf just tell the computer how much air is being pulled into for timing and injector pulses. at least to the best of my knowledge, theres not much you can adjust if anything on a afm. maf you cant adjust it, i know that one.

WickedFast.Inc 11-12-2012 07:46 PM

Mine has a flap inside and if you take the black cover off the top there is a black plastic gear with the number 500 on it every 15-20 teeth it is hooked to a metal bar that runs over a metal stip floats actually and i can adjust it so the starti g position of the flap is different

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WickedFast.Inc 11-12-2012 07:47 PM

I also found that if i make the starting position near closed i get low acceleration if i put it say halfway i can get 0-60 in like 4-5 sec rather then 7

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Nick323 11-13-2012 12:32 AM

AFM adjustment
You have got a VAF that is easy to adjust on a Dyno :)
Run it a WOT @ 4000 RPM and get somebody to turn the plastic gear (with its stop temporarily removed) to read about 13.2 AFR or 3 to 3.5 CO then arrest the gear again :bigpimp:
I am sure the manual (which fits in 3 ring binders) also tells you something, should you not be able to do it the way I usually do it.

MAP sensor measures maniold vacuum and is best tuned with a Unichip
MAF sensors are the best :thumbup: as they measure the actual air mass entering the engine. These can be "tuned" with some shunt resistors, should you not be able to afford a Unichip.

If you do not have the availiability of a Dyno, you can ask somebody expandable to kneel on the fender whilst you floor it down the road in 4'th & :rofl:
I know I am going to get sued & I do not care as our judiciary has ground to a halt years ago :tsk:

tim96 11-16-2012 12:23 AM

I may be wrong but..
The screw on the afm is for air / fuel ratio at idle and should only be adjusted while monitoring air / fuel ratios

There is no idle adjustment screw on the throttle body, just a screw which controls closed position of the throttle (which sits just passed right angle to the throttle body).

The idle is controlled by the idle control valve. If you open your throttle slightly from closed you should hear the idle control switch 'click' and 'click' again when you release the throttle. That is how the car knows whether it should idle the engine.

It is not uncommon for people to adjust the screw on the throttle body thinking it is the idle screw, this is incorrect practice.

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