How to recalibrate an AFM?? - Alfa Romeo Forum
You are currently unregistered, register for more features.    
Thread Tools Search this Thread
(Post Link) post #1 of 1 Old 01-09-08 Thread Starter
Status: -
AO Silver Member
BigAl33's Avatar
Join Date: Feb 2006
Location: U.K Surrey
Posts: 2,355
Images: 4

Member car:

Alfa 33 1.7 16v

How to recalibrate an AFM??

Hey guys, I have a 16v which would not pass emissions. I put on a borrowed unopened AFM, I didnít have time to set idle mixture and it would pass fast idle emissions at 2.5k rpm ok.
My AFM had been opened by the previous owner and had the 5min mod made to it. There is a mark on the plastic toothed spring tensioner, but I have no idea where the original resting place should be.
It has been suggested that I recalibrate MY spring tension by using an unopened AFM as a reference, but wasn't told which pins to get the readings from.

[quote]Hi, the easiest way to recalibrate an AFM that has been tinkered with requires another known good AFM. You'll need a source of air flow, like a hair drier or a vacuum cleaner, and make some piping to adjust the AFM to the flow source (use duct tape and plastic bottles).
Adjust flow until the known good AFM has a flap openend about 50%. Measure the resistance on the connector. Using the same flow, calibrate your AFM until you read the same value. Check again with lower flow (drill hole into your piping to release some of the flow) and compare that both AFMs still show comparable measurements.[quote]

Looking at the connector on the AFM and using the left pin as 1 and the right pin as 5, what pins do I read from to get resistance from the flap?

There are 5 pins and I assume 3 readings, air temp, idle mixture and air flow.
I tested by trying pins 1 through to five, then pin 2 through to 5 ect ect and only noted down if there was a change when moving the flap or the idle mixture screw.

I took a reading on the 20k range and got the following readings, this is off the car in the stationary position.

For the flap

Pins, reading
1&4, 2.09, changed with heat
2&4, 0.06, no change with heat
3&4, 0.38, no change with heat
4&5, 0.07, no change with heat

For the idle mixture

Pins, reading
1&5, 1.76, changed with heat
2&5, 0.01, no change with heat
3&5, 0.36, no change with heat
4&5, 0.07, no change with heat

The following pins gave no change for Idle or Flap

Pins, reading
1&2, 1.81, changed with heat
1&3, 2.17, changed with heat
2&3, 0.36, no change with heat

Help, where do I start???

Alfa 33 16v

Click the link below to see what I'm doing to raise money for cancer research
BigAl33 is offline  

Go Back   Alfa Romeo Forum > Supported Alfa Romeo Models > Technical & Vehicle Assistance > Alfa 33, Sud & Sprint

afm , recalibrate

Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

For the best viewing experience please update your browser to Google Chrome