Author Topic: Reseting the AFM to factory setting (Read 3291 times)

spanish_pants · « **on:** December 12, 2011, 03:54:52 AM »

Well gentlemen that is the question. Mine has been tampered with by the previous owner, and then by a less than knowledgable shop after i added some mustang injectors.
I need to get it back to stock so i can get the new chip working properly with the new injectors.

Thanks!

DesktopDave · « **Reply #1 on:** December 12, 2011, 07:19:16 AM »

Sounds like a good idea...but there's a possibility that they were all separately calibrated.

I'll see if I can dig up more info. It's a voltage curve that they put out, I'll bet Bosch calibrated them on a flow bench.

bmwconnect · « **Reply #2 on:** December 12, 2011, 09:43:46 AM »

desktop is correct, they were all separately calibrated at the factory.

spanish_pants · « **Reply #3 on:** December 14, 2011, 06:40:31 AM »

Really? would it be best to just get a new one or have it adjusted to work with the new chip and injectors?

bmwconnect · « **Reply #4 on:** December 14, 2011, 01:09:22 PM »

The best way to get it back to stock, would be to run the stock chip, remove stock lambda sensor, and have someone hook up a LM2 or equivalent sensor to measure the exhaust gas. Adjust spring till you see 13.5 AFR, then you can stick your performance chip and injectors in.

All the best!

bmwman91 · « **Reply #5 on:** December 14, 2011, 03:41:20 PM »

My advice is to find one at a junk yard that doesn't appear to be tampered with, and use that. If you are feeling like spending money, you can get a Python Injection rebuilt one, and send in yours for a core refund. It may run you around $200.

Otherwise, you will need a wide-band O2 sensor and some trial & error to get this one close to its original calibration. Sorry it isn't a cheap, easy answer!

spanish_pants · « **Reply #6 on:** December 16, 2011, 03:49:58 AM »

Quote from: bmwconnect;108894

The best way to get it back to stock, would be to run the stock chip, remove stock lambda sensor, and have someone hook up a LM2 or equivalent sensor to measure the exhaust gas. Adjust spring till you see 13.5 AFR, then you can stick your performance chip and injectors in.

All the best!

Right now i�m not running the chip. In order to get it to work properly i need to install an o2 sensor, but i am running the mustang injectors. With out an o2 sensor these were running rich, hence the previous afm adjustment.

I think i�ll go back to stock and take youre advice as a first option as it seems the most cost effective route. If this fails then i�ll just go with a new or rebuilt afm.

spanish_pants · « **Reply #7 on:** December 16, 2011, 03:53:43 AM »

Quote from: bmwman91;108900

My advice is to find one at a junk yard that doesn't appear to be tampered with, and use that. If you are feeling like spending money, you can get a Python Injection rebuilt one, and send in yours for a core refund. It may run you around $200.

Otherwise, you will need a wide-band O2 sensor and some trial & error to get this one close to its original calibration. Sorry it isn't a cheap, easy answer!

It�s tough to find these at a JY, as there are very few is�s and what there is has been sitting there under the elements for years. Let�s see if my first option pans out.

DesktopDave · « **Reply #8 on:** December 16, 2011, 07:23:54 AM »

I'll bet there are a few equivalents...my E34 525i had a very similar AFM, I wouldn't be surprised if it was exactly the same. The updated later round connector is the only change that's significant.

http://bmwfans.info/parts/catalog/13627558785/

All the M42 & M44 units are interchangeable according to the BMWFans x-ref above.