How to adjust an air flow meter spring wheel. Go counter clockwise for richer and clockwise for leaner. Most ARMs cone from the factory set very.lean. The Bosch standard is best lean burn. Set idle
Jesus sir you might have just saved my bimmer.. I've been trying to figure out why I'm running so lean at 1400 steady and now I know why.. Thank you so much for this informative video!
At risk of resurrecting an old thread, I did this with my '82 Porsche 928. I moved the spring counter-clockwise by 6-7 teeth. Wow, it makes a difference on how quick the throttle response is now. What this does is actually change the resistance to opening the air meter given the command from your right foot. Out of the factory, it is set for relatively slow (higher tension on the spring or clock-wise). This results in a leaner mixture (a byproduct of the change in the spring tension) as you push the throttle and results in slower throttle response and better emissions (not entirely sure about the emissions part). As I said, the throttle response is MUCH quicker now! Really quick and inexpensive performance mod for an L-Jet system.
I live in Australia, and we have an old car called a VK Commodore. Some were carb fed and others EFI. I had just done an EFI conversion, and started playing with the AFM. The unit looks identical to this one. Thanks for giving a rundown on how to enrichen/lean.
This helped me! I was running rich the afm was factory set. Running on LPG i had really toxic exhaust and the car was running really slow. As you know LPG uses more air than gasoline for the correct mixture, mine was running rich on LPG and low on air. Resulting in poor torque toxic smell and bad gas mileage. Ive been fought with this searching for air leaks sensors and so on. But after I have opened the AFM and set it 3 click clockwise making the mixture leaner. The results amazed me, the acceleration dynamic is better, the toxic smell is gone, the car is running really smooth cant belive!
Also, here is another ti[p I learned on my own. When you AFM starts messing up, most times the sweep arm isn't contacting the board. Had this happen on my 745i and later on on my e30 it would miss at 4,500 and at 5,000 rpm. it would buck, pull to 5,000 and then buck and pull again to redline. I took off the arm, bent it down slightly to increase contact pressure and bam. Problem solved. Same thing on the 745i, except it ran way worse, whenever boost came on it would run like crap and then die until it sat for a while. Couldn't figure it out until I saw the arm and pushed it down. Instantly it idled right, so pulled the sweep arm off and bent it slightly down and voila! fixed.
Actually the problem is not in the down pressure of the viper (sweep arm) but in the resistive trace wear out. Since you bend the viper you slightly change its track to a fresh and not worn out one and it starts working.
Thank you sit for this simple yet great video!! I've been running lean to the point of my exhaust manifold glows when open throttle for 10min+. Until I can figure out exactly what's causing this I will try this modification to keep my truck safe. Who knows, the AFM could be the problem, but it is a newly rebuilt one so not sure. Thx again!!!
Thanks for your quick response. I have a 85 manual beamer 318i. I did a mayor tune up, including valve adjustment before the test, but the vehicle did not pass the emissions test. When I checked the oxygen sensor, even though it is new, the reading was 0.8 volts. I disconnected a vacuum line but the oxygen sensor reading was still 0.8 Volts. When I manually adjusted the air flow sensor lean it out (clockwise) and confirmed the oxygen sensor reading, it showed that the O2 sensor started fluctuating. I checked the gases with the 5 gas analyzer and this time the emission readings were much better.
AEM makes a wide band AFR gauge kit that you can use for the ECU Lamda input and see your AFR. This can help you dial in your exhaust gas NOx and Hydro Carbons. High NOx = too lean. High Hydro Carbons = too rich
85 4runner hasn’t been running in 10 years…brand new battery, ran 12 volts directly to the fuel pump and it runs/ turns on, cleaned throttle body. When I spray starter fluid into the manifold, vehicle bogs and hiccups to start up…that tells me it’s getting pressure. it actually ran for about 10-15 seconds til the starter fluid dissipated. No response when I throttle. Only when I used starter fluid I rev’d it pretty high.
Problem with the click method, on my aw11 mr2 anyways, is the fp is designed to turn on if I lean the wheel too many clicks. In the end by clicking my AFM, I am just trying to compensate for a bad part or faulty wiring. I clicked right and left and each one begins to change the vehicle along with adjustment of the air bypass which leans out the system as well. After I put ECU out of diag mode, the system ends up running better in the factory position. My car has an FP switch, TPS, and other timers on the AfM that work with the ICV and dist and injectors making this kind of adjustment only ok for a few clicks in either direction. It's a good method to diagnose the vehicle, however, in the end, if the ECU isn't adjusting for variations in the octane and temperature at the factory setting, them it's either a bad AFM or other parts linked to it.
are you moving both ends of the spring an equal amount ...the vid shows you messing with one end guess both ends should move same amount of clicks? thanks
I have a few mods. High flow filter, no cats and 2.5" exhaust and Throttle cam. When I do my timing belt I'm also throwing in a 4degree offset key. How many teeth clockwise would be recommended?
Hi, I need your help. I have 88 e30 m20b25 082 coded afm. To make the mixture richer, which way do I have to turn the black wheel? Clockwise or anti clockwise? Thank you🙏
I have a issue on my 89 525i. Driving around 80mph for 5-10 minutes will give a check engine light as long as your still holding gas and light goes away most of the time when you remove your foot off the gas pedal. Sometimes it will go to a complete stop from highway speeds but not stall, just poor revving. Any ideas folks?
So if my 320i M20B20 when its cold outside it have white smoke from exhaust and rev better at cold, but loses power when warm, what and how many clicks should i adjust? 7 clockwise clicks leaner?
I checked every sensor in my system, replaced my DME coolant sensor (it has an injector type plug under the front runner of the intake manifold of my Porsche 944 NA N/A), fuel filter, fuel pressure regulators, intake manifold gasket and cleaned my fuel strainer. I'm sure all that helped but, the car was running too lean, I adjusted my AMF accordingly to the video (counter-clockwise) to make richer and all good now :) PS: I used my MPG gauge to dial in my tune to 35 on the MPG gauge at a cold start :)
Mine was adjusted by mechanic which way I dont know, car is stalling when engine is cold its around (1000rpm) when engine warms up it drops to 800 and car runs fine, can this be fixed with adjusting or just coincidence?
Hello Vern2765, I own a 1984 Porsche 928S US version with L-Jet . Recent dyno shows better than stock HP and TQ , but also shows very lean AF ratio. Your video was recommended to me , I am excited to see if the Dyno results can be improved . I have sent your video to one of the USA 928 parts supplier / racer ( Carl Fausett ) . Gonna see what Carl says . I hope i can use your solution . I hope maybe i can do this adjustment myself . I was told to turn the dial 11 clicks counter clockwise . I hope you get my message , and can reply . Thank you . ....Susan Jan 2019
Susan - please be sure to index the wheel by marking it in some way so you can put it BACK if this turns out to be a bad idea. I suggest 10 "clicks" by my match, not 11. Other than that, it seems likely this might help. Please report back what your results are!
My 77 280z runs and idles great, until you step into it and put it under a load, than it bogs down and almost dies. Would the issue likely be the AFM? Cleaned fuel tank, new fuel pump, new filters, plugs, etc.
moparmusclecars Did you fix that issue? I have the same issue on my 89 525i. Driving around 80mph for 5-10 minutes will give a check engine light as long as your still holding gas and light goes away most of the time when you remove your foot off the gas pedal. Sometimes it will go to a complete stop from highway speeds but not stall, just poor revving.
But why would you have to change the sweep arm idle position setting by changing the spring. The is a idle mixture screw that does the same it changes the amount of air that bypasses the afm (unmetered air). You also don't need to bend the arm when there is bad contact. Clean the black strip with alcohol, if that doesn't help loosen the circuit board and a bit back toward the sweep arm pivot and the arm rides on fresh black strip. Just an idea. I just don't like to mess with factory settings.
You can remove the circuit board, elongate the holes, and put it back with an offset so the contacts sweep across fresh resistive material. Tweeking the wiper arm is easier. Adjusting the spring tension has nothing to do with the idle position. It allows the door within the AFM to move more or less easily which effect the air-fuel ratio at a given RPM.
Heiko. Factory settings are for a new car. Is your car new? That screw is not an idle mixture screw. I'll buy you a beer if you know it's true purpose.
Vern2765 .right, it is not a idle mixture like on a carb where it actually control a fuel amount going through a jet. In this case it controls a bypass that allows air to bypass the afm gate. So you actually increase or decrease unmeter air that passes through the afm system. It does have an effect on the entire range from idle to full throttle.
Vern2765 hey Vern, it has been 2 years since I first posted my comment. I have found pretty good instruction on how to work the AFM. I think it only makes sense if you have access to a wide band oxygen sensor/tester. here the link of the instruction I have followed in the past. www.itinerant-air-cooled.com/viewtopic.php?t=7761
Great video.. But I find it impossible for your vehicle to run 7 steps out of adjustment in either direction, you’re state must be blending 1:10 fuel ratio ? I just did this to mine 1 tooth richer. It’s like night & day difference owning the same truck since ‘02. I’ve read other articles that 1 tooth makes a HUGE difference, so take small steps.. But 7, the door in your maf must be completely closed off having to force it open, or it’s just wide open. It depends on the elevation you live at also living @ 4300ft above sea level !!! Lol..😂
What the hell? Even though my AFM is a bit newer, there is no way to access the board underneath to move it ever so slightly if the carbon track has worn other than messing with that exact screw. That being said, a slightly newer versions seem to have wiper arm connected to amplifier board.
Very good video!! I so needed this. I have an 85 vanagon there is no obvious entrance into the AFM to make the adjustment no screws. Can anyone help, I would appreciate. ✌
Need to pop the black plastic cover off with a flat head screww driver. Be gentle and just pry it off stating at the corner closest the plug. Some are glued on so take your time.
You have to drive the car with an active Wide Band Air/Fuel Ratio gauge and tune into the "green" range at 1500 to 2500 RPM. Or about 14.0 AFR. Lower numbers are richer, so 13.6 to 13.0 at wide open throttle will get you there.
I have a question. Is it possible to adjust the gear moving clockwise leaner or counterclockwise richer using the oxygen sensor reading. If I connect my voltmeter to the oxygen sensor, voltage is between 0.1 to 0.9 Volts. Is it possible to adjust the Air Flow sensor using the oxygen voltage readings instead of the Wide band Air Fuel Ratio Gauge. Thanks Thanks.
Good idea, but no. You need a wide band O2 sensor and AFR meter to see the air/fuel ratio (AFR) The voltages you see on a VOM will swing and do not give an accurate readout.
Happened to me in 1984. So rotate the gear the other way---and try to start the car. Have one person start and and one person rotate the gear. You will find a position where the car starts and then you can adjust it.
Okay.. whenever you say 'never-ever' I start for the lever. I appreciate your observation about 'types' of fuels used in the 80's.. CRC MAF cleaner, a non-toxic sealer for the lid, sealing the unit and making sure that you have no cross contamination from you fingers (oils) and bypassing the pressure arm contact with a solder job and 4" wire. I have a 1985 Digijet system on my Vanagon and experienced the BUCKING issue at 2750rpm. Only thing that you can depend on is if your are driving in any gear, as you hit the 2750rpm range.. WILD BUCKING so sever that it shook off the meter from the rubber grommet/shroud going into the engine. BOSCH in their infinite wisdom does not make any replacement parts, GOWESTY designed their own system to replace the DIGIJET and DIGIFANT systems at a craaaazy price of about $2700, soon available. BMW/PORSCHE/VW/AUDI all using the same basic style of equipment.
@@chriscutrona5702 My airflow meter was actually out of spec when tested … 2 of the tests didn’t show OL (open loop). I went to the junkyard and I found one from a 1990 pick up, I did the test there and all tests passed. Immediately when I put it in my truck it had way more pep....no more dead spots when accelerating under load. And my “rough idle when warm” gremlin went away lol. Best $125 I’ve spent so far.
There is the Carbon Monoxide adjustment screw. It adjusts the CO level at idle to 2%. A long defunct procedure from the era of poor quality fuel. It literally does nothing today.
Only to a certain point. If you want mileage, buy a Prius. BMWs are not economy cars. The motto has always been, "The Ultimate Driving Machine," not "tighter than a Honda."
In stock form, the 22RTE uses an air flow meter, aka AFM, flapper door, or vane-type meter, to measure the amount of air entering the engine. Please get this bit of terminology right, as an AFM is not a MAF (mass air flow meter), nor is it a MAP (manifold absolute pressure) sensor. An AFM measures air flow through what is essentially a mechanical process, where incoming air deflects a flap in an enclosed space. More air coming in = more deflection of the flap. Crudely speaking, a potentiometer is connected to the flap, and as the flap moves, the potentiometer moves, and this shapes the electrical signal that is sent to the ECU. To control the movement of this flap/aramture, the AFM is fitted with a flat-wound spring that is used to apply tension to the flap. This spring is held in place, and adjusted, via a plastic gear and a wire "holder". When this gear is tightened (turned clockwise) relative to the flat wound spring inside of it, it becomes harder for the door to open, and this translates to a leaner mixture (more air needs to flow in to move the door by a given amount, meaning theat the mixture is leaner relative to its starting point before adjustment). Turning the gear counter-clockwise has just the opposite effect, as the looser gear lets more air in relative to "stock". Remember: Turning the gear CLOCKWISE LEANS OUT THE MIXTURE. Turning the gear COUNTER-CLOCKWISE RICHENS THE MIXTURE.
Sleek s, My mr2 has plagued me for years. I have the hunting idle thing going on and years ago I messed around with this click method only to reseal the unit afterwards. I've tried it yet again after watching this video and still I end up dialing it all back. I have am AFM, ICV, TPS, and dist w/ an injector timer built in. If all the basics are good, ie, timing, belt tightness, dist timing, coolant temp sensor, TPS adj, bleed coolant syst, 2 good ECU'S w/ same effect, what else could make the AFM flap physically move to compensate in a perfect rythym of about 500 rpms? Tighten the spring and I can get her to stop hunting...But, after diagnostic mode, it starts to come back at a higher RPM. If I go too loose, it won't idle at all and will run only on cold start injector. *also, leaning it out trips my FP to come on due to a metal tab along the rotating AFM internals* That's man, just asking cause you know these sensors well. It's as if someone is hitting the gas over an over again, yet, no extra fuel is being pumped. It must mean the mix is leaning and riching out to compensate, thus, the engine revs which makes the flap open. I am thinking the AFM flap is the effect of a mixture that goes lean and rich in succession...What would cause this bouncy fuel mixture?
Both. Calibrated for Professor Bosch's "best lean burn." If you loosen tension on the spring, you enrich the mixture throughout the throttle range by about 3% on each click.
The only way to correctly change the air fuel ratio is by changing the mapping of the DME. In closed loop operation the oxygen sensor input will determine the duty cycle of the injectors.
The only way to know is to use a wide band oxygen sensor with a digital readout. AEM is a good brand. Typically, you will see idle air/fuel ratios (AFR) between 14.7:1 and 16.0:1. That does not matter. At wide open throttle, shoot for 13.5:1 AFR
No. Gas mileage is a function of Professor Bosch's "best lean burn" principle, which is for fuel economy, not performance. In this video, I am tuning for performance, based on the Air/Fuel ratio needed to pass California emissions standards. Best lean burn + modern California fuel, which is not truly gasoline = failed emissions testing. This is due to high NOx.
Could you please do a video of factory setting of AFM. Some idiot touched my afm and air - fuel mixture is a disaster. On low rpm is ok but after 3500rpm is total waste of fuel. It is rich by double. Tnx
scbonduk I've tried 2 AFM and car won't run, it idles at 200rpm smokes blue and bangs blows etc. Could a weak fuel pump couse this. On my AFM wiper arm is open much more, and car starts idles but mixture is rich, I can sense petrol out of exhaust and performance is weak. Also I have a direct LPG conversion and car runs perfect on LPG also it accelerates like a dream
Filip Udovcic If you can smell fuel and there's black/blue smoke when you start then it's running rich, so pump isn't an issue. Could be a range of things causing a rich mixture though.
scbonduk yeah. And it starts hard when hot, sometimes it starts normally sometimes not. Then I've found on Internet that a bad coolant sensor can cause bad start so I've replaced it. Same thing happened. When I remove connector from that sensor car starts normally and runs much better but idle is mostly good but sometimes it won't go back to normal and stays at 1700rpm. Also it accelerates better when sensor unplugged.
Man, some update from me, I've changed the fuel pump with OEM and car finally runs great and power is back. I've refurbished AFM and set it like yours, i think fuel ratio is good because car is running very good and performance is awesome. Mine is m30b30 5 speed manual which is more sporty than a automatic
Should be very careful with this. Most of the time this is the wrong decision, people often overlook other problems and try to cover up the symptoms with AFM adjustment. A rich setting will cause power loss, waste fuel, damage your cat and make the exhaust stink. If an AFM has been tampered it is difficult to get it dialed back in. Early AFM's are more tolerant of sloppy settings as the output voltage is in proportion to air flow rather than flap angle. Later AFM's are calibrated to flap angle and small changes have a major effect on fueling. The spring tension is the major factor but the bypass setting is very important as well, if this is not right it will completely throw off the 02 sensor correction. In my experience, don't do it. My e28 had been messed with and while the wideband 02 got it close on the spring tension it still required a lot of effort to fine tune it before the hiccups and driveability were resolved.
Hi, my mechanic recently adjusted the idle mixture screw, and now my e28 stalls when warm, did your car faced the same issue? How is this affecting the o2 sensor and fuelling system
Every serious guide I've read strongly urges owners not to touch the spring mechanism at all, let alone '7 clicks'. If you want to understand how the AFM works, look up FR Wilk's knowledgeable guide. Moving images and a confident-sounding voice do NOT mean someone knows what they're doing...
David, your input is appreciated. Unless you are measuring AFR under driving conditions, anything you or FR Wilk is saying is esoteric. California emissions testing results do not lie. When you meet emissions standards, in California, your car is running well. Period.
@@vern2765California also says men can have babies and mothers can have wieners I’m not using them as a standard 😂 edit while I agree with your method (great info) don’t ever use crazy comifornia as a reference 😂
THIS VIDEO IS FULL OF BS! If your vehicle is running lean something else is wrong. DO not touch this adjustment. YOur just going to Screw the thing up, like others have noted here!
Jesus sir you might have just saved my bimmer.. I've been trying to figure out why I'm running so lean at 1400 steady and now I know why.. Thank you so much for this informative video!
At risk of resurrecting an old thread, I did this with my '82 Porsche 928. I moved the spring counter-clockwise by 6-7 teeth. Wow, it makes a difference on how quick the throttle response is now. What this does is actually change the resistance to opening the air meter given the command from your right foot. Out of the factory, it is set for relatively slow (higher tension on the spring or clock-wise). This results in a leaner mixture (a byproduct of the change in the spring tension) as you push the throttle and results in slower throttle response and better emissions (not entirely sure about the emissions part). As I said, the throttle response is MUCH quicker now! Really quick and inexpensive performance mod for an L-Jet system.
I live in Australia, and we have an old car called a VK Commodore. Some were carb fed and others EFI. I had just done an EFI conversion, and started playing with the AFM. The unit looks identical to this one. Thanks for giving a rundown on how to enrichen/lean.
Thanks for posting this!!!! I've always wondered how to adjust my afm.
This diy helps me so much, oxygen sensor low fuel/air mixture too lean has gone and power is back!!
Thank you! You saved my money, nerves and time with my Audi 80 B4 2.0e 😎
This helped me! I was running rich the afm was factory set. Running on LPG i had really toxic exhaust and the car was running really slow.
As you know LPG uses more air than gasoline for the correct mixture, mine was running rich on LPG and low on air. Resulting in poor torque toxic smell and bad gas mileage.
Ive been fought with this searching for air leaks sensors and so on. But after I have opened the AFM and set it 3 click clockwise making the mixture leaner.
The results amazed me, the acceleration dynamic is better, the toxic smell is gone, the car is running really smooth cant belive!
Thank you so much this really helped me with setting the airflow on my old kadett gsi that im restoring
Also, here is another ti[p I learned on my own. When you AFM starts messing up, most times the sweep arm isn't contacting the board. Had this happen on my 745i and later on on my e30 it would miss at 4,500 and at 5,000 rpm. it would buck, pull to 5,000 and then buck and pull again to redline. I took off the arm, bent it down slightly to increase contact pressure and bam. Problem solved. Same thing on the 745i, except it ran way worse, whenever boost came on it would run like crap and then die until it sat for a while. Couldn't figure it out until I saw the arm and pushed it down. Instantly it idled right, so pulled the sweep arm off and bent it slightly down and voila! fixed.
Actually the problem is not in the down pressure of the viper (sweep arm) but in the resistive trace wear out. Since you bend the viper you slightly change its track to a fresh and not worn out one and it starts working.
thanks I needed some help guys you rocked it for me
Thank you sit for this simple yet great video!! I've been running lean to the point of my exhaust manifold glows when open throttle for 10min+. Until I can figure out exactly what's causing this I will try this modification to keep my truck safe. Who knows, the AFM could be the problem, but it is a newly rebuilt one so not sure. Thx again!!!
Thanks for your quick response. I have a 85 manual beamer 318i. I did a mayor tune up, including valve adjustment before the test, but the vehicle did not pass the emissions test. When I checked the oxygen sensor, even though it is new, the reading was 0.8 volts. I disconnected a vacuum line but the oxygen sensor reading was still 0.8 Volts.
When I manually adjusted the air flow sensor lean it out (clockwise) and confirmed the oxygen sensor reading, it showed that the O2 sensor started fluctuating. I checked the gases with the 5 gas analyzer and this time the emission readings were much better.
AEM makes a wide band AFR gauge kit that you can use for the ECU Lamda input and see your AFR. This can help you dial in your exhaust gas NOx and Hydro Carbons.
High NOx = too lean.
High Hydro Carbons = too rich
Thanks for the information
Базара нет Рахмет тебе. А то у меня мазда 626 и меня штрафанули за превышение выхлопа. Вот теперь все исправлю.
Thank you for the post mate. Good info.
85 4runner hasn’t been running in 10 years…brand new battery, ran 12 volts directly to the fuel pump and it runs/ turns on, cleaned throttle body.
When I spray starter fluid into the manifold, vehicle bogs and hiccups to start up…that tells me it’s getting pressure. it actually ran for about 10-15 seconds til the starter fluid dissipated.
No response when I throttle. Only when I used starter fluid I rev’d it pretty high.
Problem with the click method, on my aw11 mr2 anyways, is the fp is designed to turn on if I lean the wheel too many clicks. In the end by clicking my AFM, I am just trying to compensate for a bad part or faulty wiring. I clicked right and left and each one begins to change the vehicle along with adjustment of the air bypass which leans out the system as well. After I put ECU out of diag mode, the system ends up running better in the factory position. My car has an FP switch, TPS, and other timers on the AfM that work with the ICV and dist and injectors making this kind of adjustment only ok for a few clicks in either direction. It's a good method to diagnose the vehicle, however, in the end, if the ECU isn't adjusting for variations in the octane and temperature at the factory setting, them it's either a bad AFM or other parts linked to it.
are you moving both ends of the spring an equal amount ...the vid shows you messing with one end guess both ends should move same amount of clicks? thanks
can u explain where i can adjust the fuel/gasoline on m40b18 engine ?
I have a few mods. High flow filter, no cats and 2.5" exhaust and Throttle cam. When I do my timing belt I'm also throwing in a 4degree offset key. How many teeth clockwise would be recommended?
Hi, I need your help.
I have 88 e30 m20b25 082 coded afm. To make the mixture richer, which way do I have to turn the black wheel? Clockwise or anti clockwise?
Thank you🙏
My 1981 has a rough idle and almost stalls, and I smell unburnt gas in the exhaust. Ideas?
Hello I have a 95 318ti how can I check my afr to adjust this? I accidentally move it to much and the whole spring unwound I need to adjust
I have a issue on my 89 525i. Driving around 80mph for 5-10 minutes will give a check engine light as long as your still holding gas and light goes away most of the time when you remove your foot off the gas pedal. Sometimes it will go to a complete stop from highway speeds but not stall, just poor revving. Any ideas folks?
ON the adjuster screw on the outside of AFM (Alan wrench) Idle mixture, do you have any data on factory setting and which way to turn it?
So if my 320i M20B20 when its cold outside it have white smoke from exhaust and rev better at cold, but loses power when warm, what and how many clicks should i adjust? 7 clockwise clicks leaner?
And thanks for the video.
I have a 90mm from a 240sx any tips on the best afm tune?
Ok im having the same problem but where do I put the wheel
Just made a video about this restoring an old 635CSI. I found the info in an old BMW manual. Pity I failed to see this b4 hand.
I checked every sensor in my system, replaced my DME coolant sensor (it has an injector type plug under the front runner of the intake manifold of my Porsche 944 NA N/A), fuel filter, fuel pressure regulators, intake manifold gasket and cleaned my fuel strainer. I'm sure all that helped but, the car was running too lean, I adjusted my AMF accordingly to the video (counter-clockwise) to make richer and all good now :)
PS: I used my MPG gauge to dial in my tune to 35 on the MPG gauge at a cold start :)
Mine was adjusted by mechanic which way I dont know, car is stalling when engine is cold its around (1000rpm) when engine warms up it drops to 800 and car runs fine, can this be fixed with adjusting or just coincidence?
Hello Vern2765, I own a 1984 Porsche 928S US version with L-Jet . Recent dyno shows better than stock HP and TQ , but also shows very lean AF ratio. Your video was recommended to me , I am excited to see if the Dyno results can be improved . I have sent your video to one of the USA 928 parts supplier / racer ( Carl Fausett ) . Gonna see what Carl says . I hope i can use your solution . I hope maybe i can do this adjustment myself . I was told to turn the dial 11 clicks counter clockwise . I hope you get my message , and can reply . Thank you . ....Susan Jan 2019
Susan - please be sure to index the wheel by marking it in some way so you can put it BACK if this turns out to be a bad idea. I suggest 10 "clicks" by my match, not 11. Other than that, it seems likely this might help. Please report back what your results are!
yes , gonna re-dyno and send results to you . this should be interesting .
My 77 280z runs and idles great, until you step into it and put it under a load, than it bogs down and almost dies. Would the issue likely be the AFM? Cleaned fuel tank, new fuel pump, new filters, plugs, etc.
There is a litany of diagnostics to go through. Your car is an L-jet system and has more electronic components to test.
moparmusclecars Did you fix that issue? I have the same issue on my 89 525i. Driving around 80mph for 5-10 minutes will give a check engine light as long as your still holding gas and light goes away most of the time when you remove your foot off the gas pedal. Sometimes it will go to a complete stop from highway speeds but not stall, just poor revving.
Clarification: If it's running rich, the opposite would apply, or could I get other issues 2001 vanagon vw 2.3i
But why would you have to change the sweep arm idle position setting by changing the spring. The is a idle mixture screw that does the same it changes the amount of air that bypasses the afm (unmetered air). You also don't need to bend the arm when there is bad contact. Clean the black strip with alcohol, if that doesn't help loosen the circuit board and a bit back toward the sweep arm pivot and the arm rides on fresh black strip. Just an idea. I just don't like to mess with factory settings.
You can remove the circuit board, elongate the holes, and put it back with an offset so the contacts sweep across fresh resistive material. Tweeking the wiper arm is easier. Adjusting the spring tension has nothing to do with the idle position. It allows the door within the AFM to move more or less easily which effect the air-fuel ratio at a given RPM.
Correct.
Heiko. Factory settings are for a new car. Is your car new? That screw is not an idle mixture screw. I'll buy you a beer if you know it's true purpose.
Vern2765 .right, it is not a idle mixture like on a carb where it actually control a fuel amount going through a jet. In this case it controls a bypass that allows air to bypass the afm gate. So you actually increase or decrease unmeter air that passes through the afm system. It does have an effect on the entire range from idle to full throttle.
Vern2765 hey Vern, it has been 2 years since I first posted my comment. I have found pretty good instruction on how to work the AFM. I think it only makes sense if you have access to a wide band oxygen sensor/tester. here the link of the instruction I have followed in the past. www.itinerant-air-cooled.com/viewtopic.php?t=7761
Great video.. But I find it impossible for your vehicle to run 7 steps out of adjustment in either direction, you’re state must be blending 1:10 fuel ratio ? I just did this to mine 1 tooth richer. It’s like night & day difference owning the same truck since ‘02. I’ve read other articles that 1 tooth makes a HUGE difference, so take small steps.. But 7, the door in your maf must be completely closed off having to force it open, or it’s just wide open. It depends on the elevation you live at also living @ 4300ft above sea level !!! Lol..😂
What the hell? Even though my AFM is a bit newer, there is no way to access the board underneath to move it ever so slightly if the carbon track has worn other than messing with that exact screw. That being said, a slightly newer versions seem to have wiper arm connected to amplifier board.
Very good video!! I so needed this.
I have an 85 vanagon there is no obvious entrance into the AFM to make the adjustment no screws.
Can anyone help, I would appreciate. ✌
Need to pop the black plastic cover off with a flat head screww driver. Be gentle and just pry it off stating at the corner closest the plug. Some are glued on so take your time.
Can anyone tell me how to get it back to factory settings if it wasn’t marked?
thank you. about how many "clicks" should the wheel be turned to reduce NOX? my bmw failed because of high NOX.
You have to drive the car with an active Wide Band Air/Fuel Ratio gauge and tune into the "green" range at 1500 to 2500 RPM. Or about 14.0 AFR. Lower numbers are richer, so 13.6 to 13.0 at wide open throttle will get you there.
i dont know how to open my afm to where i can see this wheel an spring
I have a question. Is it possible to adjust the gear moving clockwise leaner or counterclockwise richer using the oxygen sensor reading. If I connect my voltmeter to the oxygen sensor, voltage is between 0.1 to 0.9 Volts. Is it possible to adjust the Air Flow sensor using the oxygen voltage readings instead of the Wide band Air Fuel Ratio Gauge.
Thanks
Thanks.
Good idea, but no. You need a wide band O2 sensor and AFR meter to see the air/fuel ratio (AFR)
The voltages you see on a VOM will swing and do not give an accurate readout.
What vehicle are you adjusting the AFM on?
Thanks
This is a 1985 E23 735i with the dirty Euro 10.0:1 compression motor. I have never failed smog with this car.
my 87 635csi has rough idle and it has a slight miss when at a constant speeds. smooths out under load. Could this be the issue? no vac leaks
My e32 735i has the same issue. Hope this solves
The gear slipped out of my hand, what do I have to do to mabey remotely fix this
Happened to me in 1984. So rotate the gear the other way---and try to start the car. Have one person start and and one person rotate the gear. You will find a position where the car starts and then you can adjust it.
@BMW DIY I owned multiple 280 Z and Zx's and they had the Bosch EFI system similar to that on the BMW's of the time.
Wait he says turning clockwise makes it leaner AND richer. Which is it?
COUNTERclockwise makes it RICHER, cuz the spring is lighter then, so the valve opens more easy, L jetronic thinks hey more air so i give more fuel.
Okay.. whenever you say 'never-ever' I start for the lever. I appreciate your observation about 'types' of fuels used in the 80's.. CRC MAF cleaner, a non-toxic sealer for the lid, sealing the unit and making sure that you have no cross contamination from you fingers (oils) and bypassing the pressure arm contact with a solder job and 4" wire. I have a 1985 Digijet system on my Vanagon and experienced the BUCKING issue at 2750rpm. Only thing that you can depend on is if your are driving in any gear, as you hit the 2750rpm range.. WILD BUCKING so sever that it shook off the meter from the rubber grommet/shroud going into the engine. BOSCH in their infinite wisdom does not make any replacement parts, GOWESTY designed their own system to replace the DIGIJET and DIGIFANT systems at a craaaazy price of about $2700, soon available. BMW/PORSCHE/VW/AUDI all using the same basic style of equipment.
How do I know the right criterion
Hello sir,
Could you please help me how to adjust my bmw e30 m10b18 afm because i think its too rich?
I have an excessive fuel consumption
Where are you located?
What car are you working on
Will this adjust so that all Ohm tests are within spec? Or just a crude adjustment?
Wondering the same thing
@@chriscutrona5702 My airflow meter was actually out of spec when tested … 2 of the tests didn’t show OL (open loop). I went to the junkyard and I found one from a 1990 pick up, I did the test there and all tests passed. Immediately when I put it in my truck it had way more pep....no more dead spots when accelerating under load.
And my “rough idle when warm” gremlin went away lol. Best $125 I’ve spent so far.
i hope this works for me .. my e34 is running soo rich that if you come close you will smell fuel from the exshust.. some steam smoke ..
Did it ever fix the problem? I have the same problem with my e30
My M44 has high HC can i do something to help itI suppose its running little bit rich or something else?
will it drive better by doing this ?
100% YES!
Dam that’s the one I messed with 🤦🏻♂️
Isn’t there an adjustment screw already on the AFM?
There is the Carbon Monoxide adjustment screw. It adjusts the CO level at idle to 2%.
A long defunct procedure from the era of poor quality fuel. It literally does nothing today.
if I make it more lean will i get better MPGs?
Only to a certain point. If you want mileage, buy a Prius. BMWs are not economy cars. The motto has always been, "The Ultimate Driving Machine," not "tighter than a Honda."
This is just what I’ve heard. Leaner you get a motor- the hotter it runs.
In stock form, the 22RTE uses an air flow meter, aka AFM, flapper door, or vane-type meter, to measure the amount of air entering the engine. Please get this bit of terminology right, as an AFM is not a MAF (mass air flow meter), nor is it a MAP (manifold absolute pressure) sensor.
An AFM measures air flow through what is essentially a mechanical process, where incoming air deflects a flap in an enclosed space. More air coming in = more deflection of the flap. Crudely speaking, a potentiometer is connected to the flap, and as the flap moves, the potentiometer moves, and this shapes the electrical signal that is sent to the ECU.
To control the movement of this flap/aramture, the AFM is fitted with a flat-wound spring that is used to apply tension to the flap. This spring is held in place, and adjusted, via a plastic gear and a wire "holder". When this gear is tightened (turned clockwise) relative to the flat wound spring inside of it, it becomes harder for the door to open, and this translates to a leaner mixture (more air needs to flow in to move the door by a given amount, meaning theat the mixture is leaner relative to its starting point before adjustment). Turning the gear counter-clockwise has just the opposite effect, as the looser gear lets more air in relative to "stock".
Remember:
Turning the gear CLOCKWISE LEANS OUT THE MIXTURE.
Turning the gear COUNTER-CLOCKWISE RICHENS THE MIXTURE.
Sleek s,
My mr2 has plagued me for years. I have the hunting idle thing going on and years ago I messed around with this click method only to reseal the unit afterwards. I've tried it yet again after watching this video and still I end up dialing it all back. I have am AFM, ICV, TPS, and dist w/ an injector timer built in. If all the basics are good, ie, timing, belt tightness, dist timing, coolant temp sensor, TPS adj, bleed coolant syst, 2 good ECU'S w/ same effect, what else could make the AFM flap physically move to compensate in a perfect rythym of about 500 rpms?
Tighten the spring and I can get her to stop hunting...But, after diagnostic mode, it starts to come back at a higher RPM. If I go too loose, it won't idle at all and will run only on cold start injector. *also, leaning it out trips my FP to come on due to a metal tab along the rotating AFM internals*
That's man, just asking cause you know these sensors well. It's as if someone is hitting the gas over an over again, yet, no extra fuel is being pumped. It must mean the mix is leaning and riching out to compensate, thus, the engine revs which makes the flap open.
I am thinking the AFM flap is the effect of a mixture that goes lean and rich in succession...What would cause this bouncy fuel mixture?
The spring was calibrated in the factory, not the arm screw.
Both. Calibrated for Professor Bosch's "best lean burn." If you loosen tension on the spring, you enrich the mixture throughout the throttle range by about 3% on each click.
my sensor spoiled, I installed in its place a tps sensor that replaces the original card and reads 0.24 volts up to 5 volts
I never thought if that. Good idea, if you mess up the gizmo inside.
th-cam.com/video/TH8M6BAYArs/w-d-xo.html
So if my BMW has idle problems so I go clock wise or counter clock wise??
You should probably clean your icv "idle control valve" lol
Which he won't have if he has Bosch Jetronic or Motronic management.
Idle problems are varied.
scbonduk. Wrong. Idle problems vary and require a full range of old fashioned diagnostics.
Vern2765 Again, how am I wrong? I never ever stated that idle issues aren't various causes. You're getting yourself confused.
The only way to correctly change the air fuel ratio is by changing the mapping of the DME. In closed loop operation the oxygen sensor input will determine the duty cycle of the injectors.
So, what can you do when your car doesn't have the oxygen sensor? 😏
@@KriegBoy run in open loop. Car just dumps gas all the time like its warming up
@@psychotogen1 mine has electronic injection and it came from factory without oxygen sensor
Simply amazing
Is this on a 3.0 or 4 cylinder?
B35 Euro
How do you know if it’s lean or rich ?
The only way to know is to use a wide band oxygen sensor with a digital readout. AEM is a good brand.
Typically, you will see idle air/fuel ratios (AFR) between 14.7:1 and 16.0:1. That does not matter.
At wide open throttle, shoot for 13.5:1 AFR
Without a A/F meter, you wouldn't be able to know if you're running rich or lean, right?
True
@@vern2765 in worst case READ the plugs.
@@914_werke read the plugs? Plugs will tell you if you are too mean or too rich, but not in real time.
I probably shouldn't mess with this. hopefully my ecu chip will help with more fuel
Has this helped your gas mileage?
No. Gas mileage is a function of Professor Bosch's "best lean burn" principle, which is for fuel economy, not performance. In this video, I am tuning for performance, based on the Air/Fuel ratio needed to pass California emissions standards. Best lean burn + modern California fuel, which is not truly gasoline = failed emissions testing. This is due to high NOx.
Could you please do a video of factory setting of AFM. Some idiot touched my afm and air - fuel mixture is a disaster. On low rpm is ok but after 3500rpm is total waste of fuel. It is rich by double. Tnx
Air flow meters were calibrated and set at facory on an individual basis.
scbonduk I've tried 2 AFM and car won't run, it idles at 200rpm smokes blue and bangs blows etc. Could a weak fuel pump couse this. On my AFM wiper arm is open much more, and car starts idles but mixture is rich, I can sense petrol out of exhaust and performance is weak. Also I have a direct LPG conversion and car runs perfect on LPG also it accelerates like a dream
Filip Udovcic If you can smell fuel and there's black/blue smoke when you start then it's running rich, so pump isn't an issue. Could be a range of things causing a rich mixture though.
scbonduk yeah. And it starts hard when hot, sometimes it starts normally sometimes not. Then I've found on Internet that a bad coolant sensor can cause bad start so I've replaced it. Same thing happened. When I remove connector from that sensor car starts normally and runs much better but idle is mostly good but sometimes it won't go back to normal and stays at 1700rpm. Also it accelerates better when sensor unplugged.
Man, some update from me, I've changed the fuel pump with OEM and car finally runs great and power is back. I've refurbished AFM and set it like yours, i think fuel ratio is good because car is running very good and performance is awesome. Mine is m30b30 5 speed manual which is more sporty than a automatic
all thumbs .boo
Funny how some people say not to touch the spring. You say not to touch the sweep arm.
The sweep arm is calibrated. The spring is a fine adjustment to the calibration.
Should be very careful with this. Most of the time this is the wrong decision, people often overlook other problems and try to cover up the symptoms with AFM adjustment. A rich setting will cause power loss, waste fuel, damage your cat and make the exhaust stink. If an AFM has been tampered it is difficult to get it dialed back in. Early AFM's are more tolerant of sloppy settings as the output voltage is in proportion to air flow rather than flap angle. Later AFM's are calibrated to flap angle and small changes have a major effect on fueling. The spring tension is the major factor but the bypass setting is very important as well, if this is not right it will completely throw off the 02 sensor correction.
In my experience, don't do it. My e28 had been messed with and while the wideband 02 got it close on the spring tension it still required a lot of effort to fine tune it before the hiccups and driveability were resolved.
Hi, my mechanic recently adjusted the idle mixture screw, and now my e28 stalls when warm, did your car faced the same issue? How is this affecting the o2 sensor and fuelling system
Tbh your engine isn't brand new that's why it was that radical..
His hand has no circulation. Adujust the watch on the wrist first!
Every serious guide I've read strongly urges owners not to touch the spring mechanism at all, let alone '7 clicks'. If you want to understand how the AFM works, look up FR Wilk's knowledgeable guide. Moving images and a confident-sounding voice do NOT mean someone knows what they're doing...
David, your input is appreciated. Unless you are measuring AFR under driving conditions, anything you or FR Wilk is saying is esoteric. California emissions testing results do not lie. When you meet emissions standards, in California, your car is running well. Period.
@@vern2765California also says men can have babies and mothers can have wieners I’m not using them as a standard 😂 edit while I agree with your method (great info) don’t ever use crazy comifornia as a reference 😂
Get your hand out of the way can't see shi%
Someone needs to learn how to use velcro or electric tape and a hat. Or a hook on the hood.
THIS VIDEO IS FULL OF BS! If your vehicle is running lean something else is wrong. DO not touch this adjustment. YOur just going to Screw the thing up, like others have noted here!