mjshira

I believe that I have an AFM problem. My 1990 964 hesitates and surges at all ranges other than the upper most of the RPM (5+). I've got a new o/2 sensor installed... so based on my searching I think I have an AFM meter issue. Two questions:

1. Is there a AFM to MAF conversion out there?

2. Can an AFM be serviced or rebuilt?


The car is not able to be driven the condition is so bad.

Thanks,

James

Strega(UK)

1. Yes there are a few MAF conversion kits out there.

2. As far as I am aware you have to get your AFM rebuilt by Bosch on exchange.

mjshira

thanks. I will see if I can follow up on your reply and determine a US based Bosch contact.

dfinnegan

Sometimes the track that the wiper arm rides on becomes intermittent. It is possible to re-position the arm on the track making use of fresh track area. I have an html page that describes this process which I downloaded from a reference I found here on Rennlist. I can't find the source link, but I'd be happy to send you a zip of the html file. Just PM me. Or wait a while and I'm sure someone will post the source link!

DaveK

The link is here :

http://members.rennlist.com/imcarthur/mafmod.htm

I did this on mine over the summer, and it solved my problem.

mjshira

were you having the same issues I am? e.g. hesitation, surging, stalling?

DaveK

Yes..... and no.

I actually have two AFMs. A couple of years ago I did have hesitation and surging - I can't remember if I also had stalling. I replaced the distributor caps / arms and both coils but it made no difference.

At that time, Christer had just spent the equivalent of a small house at 9M, and therefore had a spare AFM which he gave to me. That totally solved my problems.

Then, over this summer I had hesitation which was initially quite rare but got worse until the car was a real pain to drive. I guessed it was the AFM since the behaviour was similar to the problems I had before - and I know the coils and dist. caps are not that old.

So - I opened up my original AFM, moved the arm and refitted it. Car has run perfectly ever since.

I'd say you have nothing to lose by trying it. It's pretty easy to remove and refit the AFM, and adjusting the arm is dead simple - so it's worth a try.

mjshira

thanks. is the adjustment of the arm a slight change? from looking at the picture it is hard to visualize moving the arm very much...

mjshira

I just started it and it is like it has a big block v8 cam or something, very low idle, lopie idle... tap the gas and doesn't react at first, then takes some throttle before starting to die...

I had the diag tool installed on my home pc until my virus protection removed it for me, gotta love windows!

DaveK

It is slight. Just undo the bolt and move it slightly up or down on the cam. The arm is flexible, so this alters the track it follows.

mjshira

will do, thanks. Wife has people over tonight so will have to be tomorrow.

f468357

When you loosen the bolt to raise the cam do you have to do anything to make sure the assembly doesn't rotate on the shaft or is it fixed? I am also thinking about trying this.

dfinnegan

The shaft is keyed with a flat side.

See this link for a write-up I pulled from the net. Sure wish I could find the source so I could give proper credit.

mjshira

Vertex has re-built ones for about 300 bucks so I ordered one. Seems these are the same AFM as used on the late Carrera. www.vertexauto.com

JasonAndreas

F.R. Wilk

I'm really curious to see what part of the AFM is "rebuilt".