Rejuvenating a Bosch Motronic Air Flow Meter

[TestaMetaDeth]

thanks man!!!!

[nyko944]

I have a question about the motronic AFM,I do have the same barn door style like yours but with the star screw,other than that,my main issue is my vehicle has some odd sputtering when i raise the rpm,the engine is in great shape when i bought just 7 days ago,i have added new spark plugs and a blaster two MSD coil,new filter and spectre intake,thought after all this would change, it is probably my afm?what do you think?

[GFVagent007]

@nyko944 Check the distributor cap/rotor if equiped. Check for leaky spark plug wires arcing out by looking for stray sparks in the dark. You can also test the airflow meter for proper operation by measuring the voltage signal sent back to the ECU for smoothness, or hook it up to a voltage source (depends on the car) and measure the output (see link in vid info). Sounds like either a misfire or running rich. Try a good injector cleaner, check engine and air temp sensors, fuel pressure, O2 sensor

[benautoparts]

I need to watch this when I have time.

[MkoneEscort]

very helpful vid, my Mazda 626 turbo 88' has the older bosch AFM, and it has done 289,000 km's. I will move the wiper arm too a new track now to see if i can fix a unknown running problem my car has (hesitates just when throttle is applied whilst driving in any gear and idle is very poor indeed, fuel ecconomy is bad also- 350 km from 40 litres is bad)

[madmax160764]

Thank man, Have a e30 318 and i just find out why my engine didnt start, the mass air flow door was stock open and by the way i adjust the resistor like you did,. Now the engine run great ! Mad

[gearheadjacobson]

You rock so much my friend! Thank you for this video, saved me 80 bucks. :)

[tenwierdufos]

Awesome, thanks for this, im going to give it a go tommorow and see if it removes my flat spot :) Dont think its been off the vehicle in 19 years so probably is worn out!

[DEWESNE]

My '85 735i has the symptoms you describe... great over about 2500rpm and crap elsewhere (where I drive 90% of the time). The vid is helpful showing exactly how the adjustment is done, not just a typed paragraph.

[osiz1]

why the hell so slow are you talking???

[nappytedd]

not laser calibrated. no one had lasers when they started building this type of AFM.

[newunborn]

i have a 84 e30 bmw 318i it looks the same as your video umm there is a star shape bolt on the top front can you adjust it from there

[GFVagent007]

@newunborn Top front of the AFM housing? Internal or external to under the black cover? It could be the air bypass adjustment for setting the mixture at idle (which is also how you adjust CO emissions at idle) if it is not inside the black covered compartment. The air bypass is near the intake side, often under a steel block off plug. Basicly, do not change anything that looks like it will change the rotational indexing of the wiper contacts in relation to the shaft.

[LittleModig]

hey cool how to .... clip.thankx. I got one question on this older model Bosch AFM.basically on the instructions your talking about at 3.0mints your talking a bout the ground wire that was not done on the older model Bosch AFM, where would I sourer the wire to I guess form the arm to ?????I don't know other than the Alum box?help please.....also what did you do for rerouting the arm on the new track of the ship board???? thank you for your clip.... 

[GFVagent007]

@LittleModig the added ground strap would need to be soldered to somewhere on the arm itself and the other end to the copper contact that reaches to the top center of the shaft. It's for a cleaner signal than the rotating contact alone. I would be sure to use high quality high strand count wire so it won't break down from flexing all the time. You basicly want to relocate the arc of the wiper, so raising the arm and bending the creases tighter or lowering the arm on the shaft and stretching them

[topman19722]

mine is a 1998 318i bmw e36 and the resistor had a few bad spots, but i can't lift the wiper arm it seem stuck, but i need to move it to shift the circuit board so it can run on a new part of the resistor. can you tell me how to lift off that wiper arm? Thanks!

[GFVagent007]

@topman19722 If it's like the Motronic AFM, you'll want to bend the wiper arm contacts to shift the contact point in or out, not by moving the board. Either by pinching the creases tighter to reduce the arm radius, or flattenning them to increase. Move the wiper up or down to maintain positive contact pressure after adjustment.The wiper assembly was held on by a clamp and pinch bolt that must be loosened. Once that is loosened, it may just need a little coercion to pop loose from the shaft.

[Howtoanything]

i have a 86 944 non-turbo. and it has difficulty starting, it starts after using starting fluid and then it starts a couple times more before needing the fluid again. would this procedure work? it is new DME relay, and clean butterfly and new air filter and all that crap.

[ILLWILL0701]

This Video is great - i had the same issue with my Air mass and i followed his steps and the car runs sweat.. good shit ( FYI the bolt on the silver clamp needs to be loosen in order to slide the wiper arm off duhh) (1983 944) tx again

[LZDEN]

good info..;-)

[oddsource]

Got to love german enginering... Porsche ftw

[LittleModig]

cool dude I was having a bit of hesitation on my bmw 325.I took it out and cleaned it w/sensor cleaner and what i did was use a drafting pencil #B carbon lead.Once clean I pencil the track with it and It runs great now.thankx Nice clip

[LittleModig]

you Smart ass!!!......that was clever jock,hahahaha.cool......u rock dude.Great clip GFVagent007.

[GFVagent007]

Stay tuned for part 2, testing! I'll make a vid showing how to properly test the AFM and some simple troubleshooting steps whenevery I get some time. Could be a few weeks with school...

[siiben]

I had some scratches on mine. Just under those two metal clips. Is this bad?

[mimoooo17]

مشكووووووووووووووووووووووووووو­ووووور

[AntiStalinist]

I wish I had tried this before replacing mine.

Without hesitation you should spray radio tuner cleaner directly on the wiper. This worked on my AFM for an entire season before I went to replacement.

[pikeythedrumfreak]

Thanks a million! car was running, but since this fix is much better! I painted my cam cover lettering in red, similar to yours, a few years ago. Great stuff!

[marcju1ce]

This is by far the most useful clip i've seen on YouTube. Thanks for putting it together man. Loved the ending where you highlighted the porsche lettering on your cam cover.

[TheSanctuaryDotCom]

Hey, nice write up. I have a 1984 BMW 533i. This is the same unit used in that system as well. My car has been shutting of at random times just whenever it feels like it. It started doing that after a mega backfire blowing the top of the sensor off and into the engine compartment. After repairing the top cover and running the car. It runs "ok" but has a shoddy idle and stalls whenever it sees fit. I just pulled the sensor and I'm going to try this now. Thanks for the info.

[sweatbutcher2k]

Thank you very much! This actually fixed my car and saved me a lot of money :D

[sweatbutcher2k]

Your a legend, i think this may fix my car!!!

[emstenglein]

I have hesitations between 2400-2800 rpm, a big hesitation when I stomp on the throttle, and some smaller hesitations throughout the lower rpm's. I'm doing this fix ASAP on my 1989 911 C4

[Citroeniste]

Great info. I have a 1984 Citroen CX with the exact problems you described. Track inside AFM is badly worn in one spot. I shifted the circuit board slightly instead, haven't road tested it yet. Can I just pull the wiper up off the shaft as you did without messing anything up? Also some more info on adding the ground strap would be great. Thanks a million!

[GFVagent007]

On my unit, the wiper arm hub was clamped to the shaft with a bolt, and the shaft has a flat side so it will go back on positioned rotation-wise exactly how it was before. It can be clamped lower or higher on the shaft to change where the wiper sits on the track, with bending sometimes necessary to ensure there is some pressure, and that both contacts touch the track. If yours is a Bosch Motronic, it should be the same, but most barn door type AFMs should be very similar, at least.

[Citroeniste]

Yeah I saw that bolt / clamp arrangement but was a little hesitant to loosen it. Think I will give it a try. I could not get one of the screws on the board out so all I could do was slightly re-position one end of the board. That improved the erratic running at that end of the range. I will try the wiper arm route and the groundstrap method now. Thanks very much for the info. VERY helpful!

Cheers, Pat

[GFVagent007]

Also, as for the ground strap, check in the video info. I added the website where I got this stuff, and it has a pretty good picture of how the ground strap goes on. You pretty much solder a wire from somewhere on the wiper itself to the metal piece that sticks out over the wiper hub and makes contact with the metal wiper arm. It's a redundant connection to improve signal quality.

[2bluefor1]

Thanks for the post,helped me fix my 944I'd taken out the front panel {4 screws}to look inside the meter for corrosion.When I put that panel back on,I bent the sweeper upwards. It was good to see how the meter was supposed to look normally.She's now fixed and the girlfriend's happy again.Thanks again

[dergrossen]

Loved this..thanks for posting.

[jkrustchinsky]

GREAT WRITE UP, going to save me from having to buy a rebuilt AFM, thanks so much, Josh