AFM - is it stuffed

[Ross S]

I copied the below from the FAQ's page off this site so no-one has to go looking for it. I followed the instructions to test the AFM and got a reading of over 10volts when measured at terminals 2 and 4, however when checked the readings at terminals 1 and 3 as per the second paragraph, it was 3.58volts - within the limits.

It doesn't make sense to me that the reading at terminals 2 and 4 say the AFM is buggered, but 1 and 3 say that it's set within limits.

Is my airflow meter stuffed or not?

THE BELOW IS COPIED FROM ANOTHER PAGE OF THIS FORUM (I don't know how to do it any other way)

TO TEST AFM:
pull back the rubber boot on the AFM connector revealing the wires. grab your multimeter and stick the probes on wire 4 (white) and 2 (1 being the closest to the airbox) with the multimeter on DC voltage. turn the ignition on and the voltage reading should be between 1.26V (lean) and 1.32V (rich). this is the base setting and if it is out then the AFM wont be able to be adjusted to a satisfactory mixture (meaning you need a new one)

and just for interests sake you can test the mixture by putting the probes on wire 1 and 3 with the key on and measuring the voltage. 3.6V is the factory setting which is lean, with 2.0V being rich. the mixture should be in the vacinity of 2.0-4.0i couldn't get the LED's to flash and therefore couldn't set it using the computer so i did it this way and set it to 3.5V (AFM resistance of 375 ohms) and then checked it using the computer and it was right, LED's flashing together.

 

[jatsvl]

I'll send you some gregory's info
hope it helps:thumbsup:

 

[vt_ss_5l]

Mate Just Get a new One on Ebay There Cheap !

 

[harry3]

if you remove the plug and theres no difference than its gone
might be worth spraying the sensor with points cleaner

make sure there are no air leaks in the rubber sections on the air intake to engine, the rubber can crack

 

[Ross S]

I mucked around with the AFM for a while and discovered that the readings as directed in the first paragraph of the test instructions, should actually say to take a reading from terminals 1 and 4, not 2 and 4. I did this and still got a reading of over 3 volts.

A WORD OF CAUTION FOR ANYONE ELSE THAT TRIES THIS- Make sure the engine is dead cold when doing this test. I did not and therefore got a high reading due to the heat in the engine bay heating the element in the AFM. I luckily realised this before spending any more money and started the car and took a reading at idle. With the air flowing over the element and cooling it, it was giving the correct reading therefore showing the AFM as good. The other way to do it of course would be to connect the wires to it while it's completely out of the engine bay and take the readings then. Just to be sure about this, I connected another AFM I had on loan and got the same readings, so it must be right.

We'll see how I go now.

 

[mag]

Check inside the AFM, if this fine wire is bust so is your AFM..

 

[mag]

I don't know what readings you'll get with wire 4 and 2 because it's WRONG...

Put the probes on wire 4 and 3. No.1 is the closest wire to the air filter box..

Now turn on the ignition and ur multi meter should read 1.26v - 1.32v..
if not ur AFM is stuffed. :ranting:

 

[snake_VL]

Ross S, i wrote those paragraphs that you have posted there, yes 4 and 2 is wrong, i have been meaning to change that for a very long time now but haven't got around to it. i think what mag says is right, 4 and 3. but i'll check it before i change it in the article on SC

 

[snake_VL]

I don't know what readings you'll get with wire 4 and 2 because it's WRONG...

Put the probes on wire 4 and 3. No.1 is the closest wire to the air filter box..

Now turn on the ignition and ur multi meter should read 1.26v - 1.32v..
if not ur AFM is stuffed. :ranting:

i only just got around to checking my thread on SC which was copied across to here, and it does say 4 and 3 and has since october so it must've been a really old version of it that you were referring to. i know that it was wrong at one stage but its all good now.

 

[mag]

i only just got around to checking my thread on SC which was copied across to here, and it does say 4 and 3 and has since october so it must've been a really old version of it that you were referring to. i know that it was wrong at one stage but its all good now.

It's still the same on here..