AFM: Those who Know please check this out!!

[Jay07]

Hey People!

In my long running saga for keep a steady idle im now switching the AFM!

I bought one from Spadge and have just changed it!

Please can you guys confirm:

1. Does it matter that the last digit of the part number is different?

original: 0 280 202 083

replacement: 0 280 202 082

will this effect the performance of the meter?

2. If the above is not an issue, should the ecu need time to adjust because the engine with the replacement one in, sounds like its having a asthma/heart attack??

Cheers guys

Jason

[Chris-W]

082 is a 325i AFM - I'll just check what the 083 is. Is yours a 320 Jay? Can't remember....

[Jay07]

Hey Chris! mines a 3.20i - Cheers J

[Dr Firefly]

If it makes you feel better Jay my 320i's running on a 325i one without any problems...

[Jay07]

Cheers FireFly that helps but i would still like to confirm via the part No. just for peace of mind that it would/wouldnt be a problem - I changed it back for now the engine was struggling with the replacement 1 BIg time, the car was shaking as the engine struggled to breath... well that the best way i can describe it... kinda like the sound of blowing/flapping your lips to make a fed up/horse sound....every other second... ppppppp.......pppppppp.......pppppppp ...... I dunno, this issue is doing my head in!!! I just want a steady happy idle......I changed the FPR whilst i was there too to see if that makes a difference!!

[SPADGE]

Jay that AFM came straight off a 320 and that ran perfectly
No idea what going on there!

[wullie325i]

hi

sounds like you may have a leak in one of your hoses?

just a thought

wullie

[k]

After changing the AFM would have thought you need to have the CO rechecked, and adjust the AFM as necessary.

[Jay07]

Jay that AFM came straight off a 320 and that ran perfectly
No idea what going on there!

Hmm Nothing is ever simple! Ok so assuming its a working unit i dont understand why the difference is so great? Does that hint to anything?

After changing the AFM would have thought you need to have the CO rechecked, and adjust the AFM as necessary.

But would there be such a difference? I need to find a realiable mechanic to check this

sounds like you may have a leak in one of your hoses?

Is there any particular hose that comes to mind chaps?? ive check most of those around/going to the throttle body! and theres no obvious leaks?

On the metal body of the AFm there is a screw at the bottom of a hole/resess that you can turn, what does that do exactly? Its an adjuster of some type??

[rj]

The hex key adjuster, at the bottom of the recess adjusts the idle mixture. Don't turn it unless you have access to an exhaust gas analyser. It effects the CO % level.

Any local garage, who do MOT's, will have one and can set it in a matter of minutes. Go to where you have your MOT completed and hopefully they will do it free of charge.

[k]

The AFM adjustment screw is normally set at factory, sealed with the tamperproof plug etc....and the CO will be 1.0% plus or minus 1/2%.
However during the life of these old girls the well meaning owner/twiddlers can have adjusted this allen screw to cure another fault without realising what the consequences are. The Haynes manual gives you all the info on how to set it in conjunction with the CO meter in the servicing section at front, and know that from my own experience that if your outside the spec. the car can be a bit rough on idle and jerky at low speed/ town mode, which seems to be a favourite problem on the Zone, and is a subject all on its own, however these great engines should be smooth and run without glitches, otherwise BMW wouldn't have sold so many.
Not saying that this will sort it in your case, but since you have changed the AFM its just something to be aware of.

[karldan]

whats the difference between a 320 afm and a 325 afm

[kam-325i]

Heres a tip for AFMs........

We all know that all AFMs are calibrated at the factory......each one is slighty different........electrically.

Have a look by the screw that is used to adjust the air by-pass for the idle C02. On the casing, near the hole, you will see 3 numbers. These 3 numbers are a measurment, in mm, ie : 14.6. This measurement relates to how far down the screw must be for that AFM to be set correctly.

[cliffybabe]

Jay any funny noises coming formt he car like a weak air leak, manifold gasket maybe???