AFM talk!

[HardKor944]

the screw under the plug,what way is rich amd what way is lean? ,my car is way to rich even with the O2 unpluged.

[AA_Ezra]

I think that only adjusts the idle but I may be wrong. With o2 sensor off I belive it will run rich by default

[John_AZ]

I do not know what plug you refer to.
Is it in one of these pictures?

Air Flow Meter (AFM) - from "The 944 Motronic DME" by FR Wilk

John

[John_AZ]

Originally Posted by AA_Ezra

With o2 sensor off I belive it will run rich by default

Correct. A bad or cheap O2 sensor will run rich as well.

A bad DME temp sensor will also cause a rich situation.

John

[HardKor944]

laptop shows that even with the O2 unpluged it goes off the factory settins in the computer and dose not move. Now hooked up it moves up and dowb like it should. Its a new sensor and the DEM sensor is new aswell. And yep the screw is the alan head on the lower right of the first pic. I have it figured out now anyways. I got it right where sh should be thank god for a laptop! Lol

[HardKor944]

and yes it defaults to a bit rich, but my car was way rich, almost make your eyes water if you were behind it! All good now tho.

[AA_Ezra]

I assume that the laptop was hooked up to the car some how? The exhaust? what kind of setup were you using?

[HardKor944]

yep mesures every thing, spark , injecter pluse, O2 sensor, CO2 from tail pipe, vacuum, crank ref. Its a custom set up a friend got for me, pretty sure he copy'd it from some where.

[sparky4017]

I'd like a copy of that program PLEASE

[alfadoc]

On the page to which John_AZ provided a link, there is a photo of an AFM at the very top. In the lower right hand corner of the AFM there is a recess with a allen headed adjuster. That recess used to have an o-ringed plug to close it up.

That adjuster varies the size of an orifice that is an air bleed. The air bleed bypasses air around the AFM flap. If you screw the adjuster all the way down (clockwise), you close the air bleed. Thus, air passing through the AFM pulls the flap open further, enriching the mixture. Screw it out to lean it out.

Mind you, I have not done this operation on a 944. Looking at that picture though, I recognize it as the same type of AFM used on the Alfas, Fiats, Lancias, and all the rest of the Italian stuff I've worked on for the last 25 years or so.

[John_AZ]

Thanks for the information alfadoc.

I do not like to randomly change factory settings. If I had access to a gas analyzer it might be different. Emissions testing is very strict.

I guess any one could:
1. Adjust the air volume on the AFM
2. Adjust the idle screw on the TB throttle body
3. Play with the FQS fuel quality switch
FQS - Fuel Quality Switch
4. Adjust the FPR-if available
5/6/7/8.....

No wonder there are cars that fail emissions and drive crappy.

John

[spec guy]

when you remove the plug to change the mixture, turn the screw clockwise and count the turns until it stops. At this point you will be full rich. turn it back to the starting point and make your adjustment.I normally mark the top so that i know how many turns from full rich it is set at. this is a very usful adjustment when smog testing

[alfadoc]

Interesting info about the fuel quality switch John; I had no idea it existed. Wish that chart had complete S2 info.

[HardKor944]

yep it works great...and sparky4017... You let me see what I can do for ya on that, program is nothing, just finding the leads and ****,but I can send a list of what I used.

[sparky4017]

Thanks let me know what i need to do

[sasquatch]

I'd like to second that question; What computer program are you using and where do we get it??????

[AA_Ezra]

ooo oo me to

[kfray]

Originally Posted by HardKor944

yep measures every thing, spark , injector pulse, O2 sensor, CO2 from tail pipe, vacuum, crank ref. Its a custom set up a friend got for me, pretty sure he copied it from some where.

It would be appreciated if you would post the details of test setup you have.
Thank you

[HardKor944]

its custom computer program. One of my friends created it for me. Its called "tuneyer**** ver 1.0" all custom done by a computer nerd type,i have been trying to compress it so I can send it threw email,but not having good luck lol might have to get him to do it. I built most of the leads for my 944 to just piggy back everything and feed the info to the laptop ( cuse I had a parts car and took the male and female wires off of) I used it for my mustang too, very easy to use and adjust things, but if you don't know what yer doin you can screw **** up real fast.