Bryans951

I was testing my AFM last night. The manual said to use test leads to connect pin x and y to plug a and b. Then test voltage on 2 different plugs. I only have 2 hands.

What should I use to connect the 2? Anybody made something to use for the plug part?

Don 944 LA

I just happen to have 2 jumpers with alligator clips on both ends. I used them to attach to the 9v battery and then to the pins for power.
when checking returning voltage, you only have to touch one pin, you can use the anything on the GROUND/RETURN line, even the one side of the battery.
Also, if you happen to have the cap off, the inside of the plug is easier to work with then the outside.

Good luck... and remember ... DON'T MOVE THE SPRING !!!!!!!!!

(edit) oh, if you don't already know ....
http://www.frwilk.com/944dme/afm.htm

Danno

I find it's easiest to just test the output voltage at the air-flow signal coming into the DME. It's the green wire with red-stripe. Hook your + probe onto that and use brown/yellow-stripe for ground. It should read as follows for a 951:

idle: 0.79-0.89 volts
45mph in 3rd gear steady-speed: 2.0-2.1 volts

There are two adjustments on the AFM. The spring-preload should not be messed with, it will change your air-fuel calibrations across the board in a non-linear fashion.

The other adjustments is the flapper-door bypass for idle-mixture adjustments. It's the allen-key plug in the hole right outside the AFM's body near the flange. It determines how much air gets past the flapper door without being measured. Thus changing idle mixtures.

SoCal Driver

Go down to Radio Shack and get the ends for the test probes that have a little spring loaded wire hook built into them. These slip on over the straight heavy wire ends.

These:



From this catalog page:http://www.radioshack.com/product.as...t%5Fid=270-334

If you search the site for "test leades" you will find the aligator end and other test leads.

Yabo

ok. i have a question about the spring tension in the afm. this is the piece with the notches right? the spring end goes on one of the teeth. Mine has a red mark on one of the teeth, and its not lined up with the other red mark on the arm or spring or something like that. or the spring end isnt at the red mark...

I dont know it was something like that. but whatever it was, didnt look like it was lined up. are the red marks, or red mark and nspring supposed to be lined up and someone just messed with mine? i put it to lining up, and it didnt change anything.

Don 944 LA

I don't think a red mark was factory installed.

Maybe a previous owner had moved the preload spring in an attempt to adjust it, and marked the factory calibration spot.

My PO had done this, only I did not know where the original spot was.