Carrera 3.2 vs 944 Airflow meter

[Kainguru]

Hi all,

Been sourcing this forum for ages for useful info and tips . . . now time for my first post (and hopefully some more good advice to help keep my object of time and devotion running)

I've gone through all the threads I can find regarding testing, adjusting and repairing the 3.2 airflow meter. What I cannot figure is what is the difference between a 944 motronic AFM and a 911 3.2. The output pins are the same, the output voltages are the same for the same degrees of deflection of the vane, they look the same and some where I remember someone saying he used a 944 AFM circuit board to repair his 3.2 AFM. In the best 944 AFM maintenance site it states that the 911 3.2 and 944 AFM's are identical.

So, are they actually interchangeable or would I run into trouble fitting a 944 AFM to my '89 euro 3.2 - as I can source a functioning '86 944 turbo AFM more readily than I can a 3.2.

Cheers in advance for your suggestions

[ChrisBennet]

I believe the diameter of the in/outlets are different. They look identical until you have them side by side. (I have what I believe is a 944 air meter in my parts stash, I could be all wrong.)
-Chris

[scarceller]

First,

Have you seen this post? 3.2L Air Flow Meter calibration research prodject

I started this post about a year ago and have a very detailed document covering these AFM devices, you can get it here:
http://members.cox.net/widebody/AFM/AFM3.2LCalibration.doc

I would love to know if the 944 Turbo AFM works as well.

As Chris already mentioned first we need to be sure the input and output bores are the same.

Then the devices measure air by means of the barn door and even if they are the same devices mechanically and electrically they could be calibrated diffrent by Bosch. Meaning the spring tension for the 944 could be diffrent than the Carrera device. But, maybe the spring tension is all that's diffrent, even if this where the case it is not that easy to calibrate these devices (read my doc to fully understand).

However, if they are truly the same this would be great info to know. If we determine that the devices have the same input and output bores then I may scoop one of these up from e-bay for testing. At this time I have the correct set of tools to calibrate one of these devices in car and compare the 944 device to the Carrera one. My WideBand O2 setup lets me compare the results of 2 AFMs via live runs in the car.

So if someone can confirm that the 944 device fits (physically) in the Carrera this would be a good start.

Thanks