Help AFM. Needed

[jesfirth]

My griff stopped on the M2 10 days ago. A dead AFM was diagnosed. The new arrived today and I fitted it. The car now runs which it did not with the old one fitted but it runs very rough and smelly very rich. Does anyone local to high Wycombe have a spare AFM I can try to see if my new AFM is a dud. Thanks. Jes

[OleVix]

maybe you need to adjust the co screw on it, its 7/32 allen key.

If you have rovergauge and a windows laptop, you can see the voltages realtime when you adjust the screw. I believe its 1.8 volts for a 500 with cats.

[A900ss]

I can't help with a spare AFM but did you replace the AFM with a genuine Lucas or an EBay/similar Chinese copy?

My AFM went so I replaced with an AFM from EBay.

Worked fine (I thought) until it went on a rolling road. It was then that I realised it was leaning out (a lot) from 2.5k upwards.

Rather than get a genuine (and expensive) Lucas, I had my car fitted with a larger AFM and had it remapped as I believe the copy AFM's are notoriously unreliable in our hot engine bays. (Google Kits and Classics for more info)

Good luck.

[jojackson4]

OleVix said:

maybe you need to adjust the co screw on it, its 7/32 allen key.

If you have rovergauge and a windows laptop, you can see the voltages realtime when you adjust the screw. I believe its 1.8 volts for a 500 with cats.

We're is is this Ole?

[blitzracing]

The CO trim only affects the non catalyst fuel map. If you have lambda probes, the CO trim is automatically set so you don't need to adjust anything. The ECU will drop into get you home mode if the AFM output is really bad- you can even disconnect the AFM completely, and the car will run on the throttle pot input- but it will be very lumpy and run rich, but it would get you home. It will also flag an AFM error code if you have the hardware or software to read it.

[jesfirth]

blitzracing said:

The CO trim only affects the non catalyst fuel map. If you have lambda probes, the CO trim is automatically set so you don't need to adjust anything. The ECU will drop into get you home mode if the AFM output is really bad- you can even disconnect the AFM completely, and the car will run on the throttle pot input- but it will be very lumpy and run rich, but it would get you home. It will also flag an AFM error code if you have the hardware or software to read it.

thanks - I wont play with anything - I thought they were plus in and forget items so pleased to see that is correct.

Sadly the new AFM seems to make no difference other that allowing the engine to run. It stinks of fuel, coughs, splutters, misfires wont go above 3000rpm. At least it runs though - with the old one plugged in it would fir up then just instantly die.

I have no cables software or anything like that - even if I had it I wouldn't know what to do with it - so a bit buggered really. Stevesprint is very kindly lending me a working AFM tonight so I am going to shove that on just to check and see if it is the new AFM that is not working. I thought I had bought a Bosch unit from Ebay (mine is larger than the original standard one) - it came from Germany yesterday but it has no Bosch stamp on it so I am a bit miffed. I paid by Paypal so if its not right I will just send it back and get a refund. Its not the money though its the hassle and that I am supposed to be sprinting the car at Prescott on Saturday!

[Bluebottle]

jesfirth said:

thanks - I wont play with anything - I thought they were plus in and forget items so pleased to see that is correct.

Sadly the new AFM seems to make no difference other that allowing the engine to run. It stinks of fuel, coughs, splutters, misfires wont go above 3000rpm. At least it runs though - with the old one plugged in it would fir up then just instantly die.

I have no cables software or anything like that - even if I had it I wouldn't know what to do with it - so a bit buggered really. Stevesprint is very kindly lending me a working AFM tonight so I am going to shove that on just to check and see if it is the new AFM that is not working. I thought I had bought a Bosch unit from Ebay (mine is larger than the original standard one) - it came from Germany yesterday but it has no Bosch stamp on it so I am a bit miffed. I paid by Paypal so if its not right I will just send it back and get a refund. Its not the money though its the hassle and that I am supposed to be sprinting the car at Prescott on Saturday!

If you are using the Larger Bosch 20AM afm, then I to have had a couple of duff ones off ebay, and even one I got from a Landie dealer wasn't genuine and didn't work correctly.

E.T.A.
Just found this on ebay;
Mass-Air-Flow-meter-Sensor

Edited by Bluebottle on Tuesday 19th May 18:33

[jesfirth]

Thanks all. The duff one off ebay is going back to Germany. Mark Adams very kindly courier end a new genuine bosch unit and it works perfectly. (-: jes