AFM Service

[rezzy3181]

:yahoo: Jarance I normally wait at the w/shop for service and so on unless can'nt help it of some urgent matters and I make sure my car as a whole is clean including undercarrage and engine compartment so they know what type of service I expect in return and I will detact my problem and get the parts first and instruct them to do it, never I asked them to check, through years of car playing and enjoyed dirting my fingers at times checking myself finding faults then go to them. its fun anway you know a little at least car don't stop while driving if its well taken care off. last two weeks I had my steering overhaul change all parts hoses waited 1 day till completed as I can't stand when hoses start leaking (I get all relevent parts myself cost a little more then 1k for parts. OK lah brother thanks for your good sharing.

 

[bazet]

Here's my experience
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I took the opportunity to service my ISV ( Idle Speed Valve ) and serviced my AFM box too. But I can't open the cover as the glue is very tight. I even try push it from inside, try to push it from outside ....and I give up

Nevertheless, I manage to service the visible part.

As for ISV, I use normal WD40 to lubricate and to clean the dirt.

Install it back and voila, no more sluggish idle. The pedal throttle is smooth, pulling response also very good.

 

[bal3056]

Jarance, Sat SriKal Ji,

Good on you, mate for a comprehensive DIY process to tackle AFM related problems.

1. I have an E34 M20 Auto. I don't have erratic idling problem, but my problem is that the idling is way too low, about 550rpm in 'D' & AC on. The engine doesn't stall or die on me. I was told the idling speed cannot be adjusted. Is there a way to solve this 'low' idling problem ?

2. The other problem is that the pickup performance is really bad and fuel consumption has become a killer. I am aware that a M20 Auto is a very sluggish car ... yes, i agree, but recently, can't accept such bad fuel consumption. RM30 only takes me about 110 - 120 kms. Wasn't like this before.

My other car, a 1980 Holden 3.3L gives me the same mileage and this is a car with very very old technology.

Can the above be due to AFM related problems?

Cheers mate.

Hatish

 

[KiNaKa]

adjust or replace the spring in the AFM, so the tension still there... ur rpm will increase faster... this is what i've tried before... hehehe

 

[jarance]

Originally posted by bal3056@Mar 21 2005, 08:07 PM
Jarance, Sat SriKal Ji,

Good on you, mate for a comprehensive DIY process to tackle AFM related problems.

1. I have an E34 M20 Auto. I don't have erratic idling problem, but my problem is that the idling is way too low, about 550rpm in 'D' & AC on. The engine doesn't stall or die on me. I was told the idling speed cannot be adjusted. Is there a way to solve this 'low' idling problem ?

2. The other problem is that the pickup performance is really bad and fuel consumption has become a killer. I am aware that a M20 Auto is a very sluggish car ... yes, i agree, but recently, can't accept such bad fuel consumption. RM30 only takes me about 110 - 120 kms. Wasn't like this before.

My other car, a 1980 Holden 3.3L gives me the same mileage and this is a car with very very old technology.

Can the above be due to AFM related problems?

Cheers mate.

Hatish

I have the same probleam as your No.2. High comsuption and lack of power.

just change the spark plugs and fuel filter and problem solve.

BTW, appreciate some feed back on the method posted for further improvement. Does it works or not?

 

[M30revival]

Well if you have done all the cleaning and still couldn't get a steady idling, time to fiddle with the interior of the AFM. The idea is to service the potentiometer inside the AFM.

I follow the instruction in this link and tinker with the arm and it work beautifully. The link within this article also explain in details the working of the AFM. Yes the older model like E23/E28 uses the same AFM in a Porsche!

Before the adjustment, I also had the same problem like BAL3056. Idling was way too low when in 'D' with A/C on. Fuel consumption was suffering as I can virtually see the needle move! After adjusting the AFM, the idling now is just nice and the fuel consumption improves (already changed plugs and plug cables before that). When I had this problem, I was also told that it cannot be fixed. One mechanic said needs to change the AFM so I got myself a spare (just in case). Another said it is due to the brakepan (sp) inside the gearbox. Well after tinkering with the AFM per the instruction in the link, I managed to get it stabilized and now the car feels very lively.

Now I have a spare AFM sitting in the trunk! Hmm.

 

[gwumpkus]

Originally posted by jarance@Feb 4 2005, 10:42 AM
To Detached the AFM from the Air filter casing, you have to remove the 4 bolt on the inside of the Air filter casing. You have to use a size 10 spanner. If you have a offset spanner, then it would be better as the bottom bolt is situated in arward position to turn the spanner fully.

just to make things easier, u can UNCLIP the little square vent pc in the picture....

helpful hint, this diy for the afm!...i'm about to pull it off and do it....now if it'll stop raining....thanx..


cheers!

michael

here is pic of what micheal is saying

 

[gwumpkus]

Originally posted by M30revival@Dec 31 2005, 05:54 PM
Well if you have done all the cleaning and still couldn't get a steady idling, time to fiddle with the interior of the AFM. The idea is to service the potentiometer inside the AFM.

I follow the instruction in this link and tinker with the arm and it work beautifully. The link within this article also explain in details the working of the AFM. Yes the older model like E23/E28 uses the same AFM in a Porsche!

Before the adjustment, I also had the same problem like BAL3056. Idling was way too low when in 'D' with A/C on. Fuel consumption was suffering as I can virtually see the needle move! After adjusting the AFM, the idling now is just nice and the fuel consumption improves (already changed plugs and plug cables before that). When I had this problem, I was also told that it cannot be fixed. One mechanic said needs to change the AFM so I got myself a spare (just in case). Another said it is due to the brakepan (sp) inside the gearbox. Well after tinkering with the AFM per the instruction in the link, I managed to get it stabilized and now the car feels very lively.

Now I have a spare AFM sitting in the trunk! Hmm.

hmmm..thats a keen site!..

now..iv'e just overhauled the afm per jarance's instructions...

dunno if it works yet, but i did get a chance to clean it out realllllll thoroughly...and did a bit of sanding here and there with fine grit emery paper...

HOWEVER, i tried in vain to remove the top plastic cover of the afm internals. one side actually lifted, but it seems to be sealed somehow.. refused to pop open... and i damaged a bit of the lip, from prying too enthusiastically..

anyone has better luck? mine's the afm from an m40 engine....

thanx guys..

cheers!

michael

 

[gwumpkus]

hmm...bad news..

the erratic idling is *still* there.... hmm... cleaned out everything i could!!..but still no use...

now i'mbeginning to wonder...could it be something else??..sigh... anyway a replacement is already on its way...delayed by year end festivities in the US....

ONE QN:

the CO adjustment screw usually has a little red rubber bung, that u have to pry out to adjust. that has gone missing!!!!.. crap..

anyway, just wondering also if anyone's been able to adjust their CO content...which way is UP/DOWN?..clockwise(tighten)? anti-clockwise?... any way to do it without having a MODIC to read the content levels?...

i remembered one mech leaned it out slightly for me before, to get slightly more lively response from the engine..but that wasbefore the tranny got swapped.

recent servicing seems to have set it back to stock levels... engine not so lively..(or have i gotten used to the miserable gains in power due to the tranny swap??..hahha...

thanx a lot for any advice..

happy new year ladies and gentlemen..

cheers!

michael

 

[jetschin]

Any mechanic here doing this AFM cleaning? Pl recommend, price estimates?

 

[longan]

very low basic question.... :dunno:


1. AFM = air flow meter rite???

2. an e34 with m50b25 having AFM or MAF????

3. modic-ed my car showing "air mass" faulty. what this mean??

4. CO adjustment can't be done even my mech turning the screw on the so-called AFM/MAF.. is that mean the "thing" really kaput??

huh.. heard can get from chop shop arround RM 600-800..
new cost 1.5k ++ i'am guess???

"welcome to the jungle" :hmmph:

 

[fabianyee]

Originally posted by longan@Mar 23 2006, 02:07 PM
very low basic question.... :dunno:


1. AFM = air flow meter rite???

2. an e34 with m50b25 having AFM or MAF????

3. modic-ed my car showing "air mass" faulty. what this mean??

4. CO adjustment can't be done even my mech turning the screw on the so-called AFM/MAF.. is that mean the "thing" really kaput??

huh.. heard can get from chop shop arround RM 600-800..
new cost 1.5k ++ i'am guess???

"welcome to the jungle" :hmmph:

M50B25 comes with MAF.

Is your engine VANOS or Non-Vanos?
The MAF is different...
VANOS - 4 pin MAF
Non-VANOS - 6 pin MAF

I don't think CO can be adjusted in the M50.. AFAIK, it's ECU-controlled. I could be wrong though.

 

[longan]

clear enaugh....!!!
mine non-vanos...
how about the price??? is it around that???

 

[Prince]

Dear all, can i know where is actual location of the Air Flow Sensor. Coz quite confuse of AFM & AFS. Sorry to ask such stupid question. Thanks!!

 

[jarance]

Originally posted by Prince@Mar 23 2006, 03:04 PM
Dear all, can i know where is actual location of the Air Flow Sensor. Coz quite confuse of AFM & AFS. Sorry to ask such stupid question. Thanks!!

here is the location of the sensor.

 

[fabianyee]

-Prince@Mar 23 2006, 03:04 PM
Dear all, can i know where is actual location of the Air Flow Sensor. Coz quite confuse of AFM & AFS. Sorry to ask such stupid question. Thanks!!

here is the location of the sensor.

that's the air temp sensor.. not air flow sensor...

 

[jarance]

Originally posted by fabianyee+Mar 23 2006, 04:37 PM-->
that's the air temp sensor.. not air flow sensor...

Oops.. you are right about it..

Fab, thanks for pointing out the error..


Come to think about it, the air flow is determined by the
degree of deflection of the vane. When more air is being drawn
into the trottle body, the more the vane have to open.
This deflection is being monitored via a resistor printed circuit
board. By measuring the change in the resistance, you can
basically determined the air flow.. I think air flow is equivalent
to the square root of the resistance change..

fab.. please confirm the above.. hate to be wrong twice in a row..

Here is a pic of how the AFM works!! (borrow somebody pic)
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[jarance]

BTW, the link that was posted earlier by m30revival is rather
informative. I would recommend you to go to the webpage
if you want more detail information about the AFM.

here the link...click below link


AFM rebuild

 

[wolverine]

Originally posted by longan@Mar 23 2006, 03:00 PM
clear enaugh....!!!
mine non-vanos...
how about the price??? is it around that???

Non-vanos MAF can b adjusted using GT1...not da screw!

B)

 

[longan]

Originally posted by wolverine+Apr 6 2006, 01:51 AM-->
Non-vanos MAF can b adjusted using GT1...not da screw!

but then... what the screw function? :blink: