AFM Change Problem

[Mccullagh246]

Hello All
I am new to the forum do you will have to bare with me if this topic has been covered recently

I have a E30 1990 325i Auto it had the usual problem of stuttering when putting your foot down and occasionally cutting out when pulling off.
i have changed temp sensors, ICV, dizzy and rotor, spark plugs HT leads, cleaned the TPS and more but it still has the problem.

i recently bought a new old stock AFM, when it was to late i found it was for a 320i not my 325i, after fitting it the car idled fine but when revved it die and would cut out.

My question is the new 320i AFM useless on a 325i ? Or is it a case of some how resetting the ECU so the car can recognise the new part?

Any help would be much appreciated

Thanks Tom

[Speedtouch]

Welcome to the Zone, Tom!

Are you sure it's a 320i AFM? Stick the part number into www.realoem.com to find out for sure.

It shouldn't be "useless", but won't be correctly calibrated for the 325i. You are probably better off servicing the original one - it's possible to bend the wiper so that it sweeps on a different part of the carbon track:



Or adjust the Air-Fuel ratio on your 320i AFM to suit the 325i:

[Mccullagh246]

Thanks for the help !!

The web site is excellent and has identified the part as a 320i afm
I am going to try and set the 320i afm to 325i setting using the video you posted.

She never had a problem until she sat in the garage for a year and now there is all sorts wrong

Your help is much appreciated! And I'm sure I will be posting again soon,

[Brianmoooore]

An 'adjusted' 2.0 AFM will only be very approximately right for your 2.5 at best. You will be far better advised to refit the 2.5 one, which, as long as any previous owner hasn't followed the extremely dubious advise in that second link, is probably OK, and to address the much more likely cause of your problems, which is a combination of various minor air leaks into the inlet tract and injectors that are direly in need of a rebuild.