Thank you very much, very informative video. These days mechanics aren't taught how to fix things, they are taught to replace when you've got a problem.
Always happy to help and thank you for the kind words! Yep, I learned the old school ways, my father is a retired licensed mechanic. I grew up with points, tuning carbs by ear, testing sensors manually, and troubleshooting with a basic scan tool.
wow! this is by far the most helpful video I've seen in a RU-vid channel. keep up the good work and thank you very much for making this video, it helped me out a lot.
A very helpful video. May I know if the carbon track has deep mark due to high mileage and frequent rubbing of contacts, can we in anyway shift the whole circuit board slightly so that a "new" contact track can be established
That is why most people slightly bend the tab/arm just a tiny bit to change the position, so the arm sity on a "fresh track". Some shops/electrical pros do have access to brand new circuit boards.
Been looking for this,now I know how easy it is a mechanic would've replaced the whole part and pay big$$..1fzfe 80's series Landcruiser 1993..thanks for your channel mate.
wow, impressive video. i feel a lot more confident working on my bmw's AFM now. i know you said to not mess with the wheel/gear, but i need to richen the a/f-mixture, to reduce NOX. thanks
Great video, I have a similar looking air mass sensor but on a different brand car.... I am going to take it apart after watching your video! Will post an update after is all done! Thanks!
Great video. One question: the bypass screw: you mentioned that turning clockwise would lean out mixture. I thought turning it clockwise would eventually shut off the bypass air, therefore enriching mixture.
+Isaac B Thank you. Nope, turning it clockwise on this particular model will lean it out. But it may vary between a couple different models as they did change over the years and there are some slight differences.
I know is likely a stupid question but I presume you cannot swap a Lucas 2AM AFM with different model number e.g. replace 0280202046 with 0281002092 - I presume they have different resistances?
Hi, I need your help.. I have 89 e30 m20b25 082 coded afm. And my question is; For rich mixture, which way do I have to turn the black wheel. Clockwise or anticlockwise? Thank you🙏
i followed the disassemby instructions as you have shown and i didnt really realize until i was about ready to pull the little black plug out of the afm, but there are two very very small wires that are connected to the plug and the small white and green board. im wondering about the importance of those two wires as they are both very weak and one of them bent off. i have an 89 e34 525i with the m20 engine, the afm seems to be the updated version because there is a wire connected to the hinge assembly like how you added to "upgrade" your afm. i hope i can get a response soon !
I got a question. I have an 1988 ford 2.3 turbo setup in my mustang and at high rpms (after 55k ) the engine stumbles and misses for several minutes after. Feeles like cylinders were shut down because my afr reading were normal the whole time it stumbles. Im trying to narrow it down. I wondering if the vane meter would cause this ?
Hi there. Extraordinary job and helpful video. Thanks a lot for doing it... I'm about to try it out, and I have a question: My car is a 318is 1993 m42, Europe, and it has been showing issues with the mixture (at the begining, just a rough idle; now it hardly starts, after changing ICV and, because of a rattle when starting while cold, the timing chain tensioner). I found it has not O2 sensor (the electric connector sealed, and no hole on the exhaust manifold); and I checked them out all the hoses, the sparks, their wires, the coils, and they are in reasonably good shape. So I tried with the MAF (at this point I realized it is more than likely it was "changed" by a mechanic guy; of course without my knowledge). Well, the MAF's housing vane sticks when being closed, at half its way, and widely open. And it is evident the engine asks for more air to start and operate. I'll test it following your previous video, regarding the Bentley Manual's specifications for its engine. As I'm sure it won't pass the test, I want to ask you: Is this procedure (changing what it's needed to change) applicable to an 1993 m42 engine? Especially the adjusting of the swipe arm to run on the track by a new place and the manner to adjust the air with the idle screw. Thanks in advance for your attention.
Jesús J. Ortega Weffe Thank you for the compliment. Yes it should be. There has been some minor changes or updates throughout the years but the basic unit is the same, even outside of BMW models. Similar units where also found on other European auto makers as well.
Excellent video! Clear, concise, and thorough. Thanks! If the carbon track is worn out, is it possible to take a solder pen (i.e., pen with silver conductive material), and just draw/write over the worn tracks? Is there a reason this wouldn't work? I was under the impression that as long as the wiper arm contacts the material and current can flow that would be sufficent.
+milkphish As far as I know you can't restore the carbon track as it works on resistance and I believe adding any soldier to the surface will ruin the resistance function.
Hi i was wondering why my bmw 1989 325i 's gas is too high cuz of the flow meter what can i do to repair it? Thanks a lot for this useful video if u could answer that i would really appreciate it .
Great tutorial! My m30b35 seems to run very rich and just drinks up as much gas as it can, will have a look at this! How would you adjust the a/f mixer without any equipment?
If you want to know what your mixture value is but don't have a lambda sensor, you could "read" your spark plugs, but that's not very precise. It's just to see if you're in the ballpark of good stoicheometry
@@__-vb3ht I measured it at the sensor, reading around 0.620 mv, being a narrow band sensor it's right around stoich. I had a dodgy blue CTS sensor plug that could've been the issue. Solved that and now it's testing time
Nice video. My viper arm when car is turned off is very loose and when I tight it up mixture is bad idle is 200rpm. I see your viper arm stands od the beginning of the black slide track mine is 1 cm further. Can you do a factory setting of afm or something similar tnx
I have a 1988 735i and I have tested and cleaned the mass meter. But I keep getting code 1224 air flow temp sensor. I tested it according to your video and I only get around 900 omhs the car stumbles and almost dies warm or cold. everything else checks out fine engine temp sensor, fuel pressure--- new filter, tps, idle control, cleaned plugs are tan all looks good. so how can I fix the temp sensor for the air flow meter, all wires check out fine?? Your numbers 1450--3300 don't even come close on mine with a hair dryer i get from 900 to 7ish?? Help if you can. Thanks
Thanks for the great Vid. I have 88 bmw e30, when I first step on gas, there's hesitation, like a flat spot, is that the wiper track on the circuit board? or air fuel mixture? Thanks again for your help
+Vincent Vizzari The flat spot could be a variety of issue. It would be best to check out my test video first on this unit to determine if you are having the same symptoms. If not, the issue could be anywhere from a dirty throttle body, other faulty sensors, or just basic tune-up maintenance.
Hey, nice work there, i just hav a technical question, i hav an e36 with an m42b18 engine, somehow i bought it fitted with a 1.6 litre manifold, does this affect my power output and fuel consumption??
+sherif mohd Thank you. I haven't really done any performance upgrades to an M42, but upgrading an intake manifold in general does have it's improvements. They will normally change the power band, may or may not increase fuel economy, and will usually increase performance.
Hi from Yemen, Please help are the circuit boards of m20b20 and m20b25 afm interchangable? ,mine is m20b20 89 e30 Metronic 1.3 dme 173 and i couldn't find a circuit board online for m20b20 afm. Please help
www.hiperformance.com has an excellent written tutorial on the complete Bosch LU-jetronic with emphasis on rebuilding an adjusting the clock spring for better performance. They recommend moving the clock spring 6 teeth to the less taught position to gain 5 HP as the engines are tuned too lean. There are some other fuel ration adjustment tips on their site as well (They specialize in Alfa's, but the system is the same if one is familiar with it.) What has peaked my interest of late is trying to find out if one can substitute the more precise thermal anemometer type mass flowmeter from the LH-jetronic for the mechanical one used on the LU/LE-Jetronic and get the system to work properly.
Site seems to be down at the moment. I'd be hesitant adjusting the ratio without taking reading from the exhaust and wouldn't want to risk damaging the catalytic converter with the added fuel. I haven't tested it myself, but apparently the O2 sensor can be back probed and then monitored with a resistance reading. I believe people are retrofitting MAF sensors in place of these AFMs. I've never done it myself, there might be some modifications of the wiring involved.
My bad, www.hiperformancestore.com/Ljetronic.htm I'll look into a little more carefully. Seems like an expensive proposition to change from LU-jetronic to CIS Mototronic, if that is what is required.
Here's an expensive upgrade I just found online, honestly didn't even know this existed www.millerperformancecars.com/store/show-by-car/e30/bmw-maf-kit-m20-m30-miller-detail But I know there is a fair amount of tutorials around to do it yourself www.bimmerforums.com/forum/showthread.php?1228729-Make-your-own-MAF-conversion-for-under-50-I-did-it Not something I'd do with this car as I'm not sure if the computer has been tuned by Hartge and it's just a relaxing cruiser anyway.
Hello! I have a 318ti from 95' and i was experiencing rough idle problems just after I bought the car and replaced the air filter. Firstly the car was showing a high rotation idle, around 2k rpm. I found some air leaks on the air hoses on intake manifold. Thought the problem was fixed... not so fast. When I started the engine, the idle became very rough and the engine came down dead. Nearly impossible to drive because the engine could not sustain the idle at aprox. 750rpm. Seeking for a solution, I found your video. Which points on the AFM should I look for when doing this review/repair? My engine is an M42. Looks like there it is not enough air passing into the engine, because when I produce an air leak on the intake hose, the idle became pretty better at 1k rpm, if I expand the leak, the idle comes up and up, just as it was before the hoses repair. The AFM its way expansive to replace, but looks like the problem is there. What should I do next? Thank you.
Gabriel Neves Yes it is quite possible the AFM could be the culprit. You can take it apart and clean the potentiometer inside. Then see how it runs and an adjustment maybe required, but be sure to have the correct equipment to determine what your air/fuel ratio is.
There shouldn't be any resistance rating in the rotational contact. The wire adds reliability to an old design which is why it's an update on newer units.
I have two AFM's, one that is original to my 91 e30 320i and one that is from unknown aged e30 320i, the latter one has 5 pins instead of 4, does anyone know of a good way to adapt it to the loom? The one from my 91 e30 is totally clogged up and won't move freely even after immense cleaning attempts. I tried moving the circuit boards and springs etc but the tip of all the screws broke off. Should I drill them out then move the circuit boards or is there another solution?
HI, Could you tell me that, this video use for R134 air flow right ? Because, I use M40 with R134 Air flow and I have no experience on fixing cars. But, I try to do
thank you very much for this video and your narration which is primarily informative and detailed explanations. I want to get an idea from you about some important nuisance. My old lady is 1981 modell E-23 745i Turbo (EUR) Air flow Meter's the fabrication settings were completely degraded some stupid technician played with a black wheel and me and bmw service can not get a setting again. this instability, the car emits black smoke and the idle is broken. How can I return to factory settings?
Oktay bey merhaba, buradaki zengin ve fakir karışım anlatımında da sanırım hata var. Size tavsiyem şudur ki, siyah dişliyi klape boşa düşene kadar gevşetin ve ardından 6 diş sıkın! Bunu aslında egsoza çubuk sokarak ve bilgisayar vastasıyla emisyon değerini okuyarak yapmanız çok daha iyi olacaktır. Lakin dediğim gibi. Klape boşa düşene kadar çarkı gevşetin sonra 6 diş geri gelin.
9:06 mine stays closed until i push it hard first time and it has a squeak after each time i move. then it seems to stuck when it passed in the middle. it takes a little push to get it to move it isn't smooth. and if i don't push it stays in the middle and doesn't open or close all the way itself without a push does this mean i should replace the whole thing or is this normal? i've only used MAF cleaner spray.
Update i couldn't get the top open as one screw stripped, but using enough MAF cleaner and working the door, i was able to get it 90% better than what it was, where it doesn't stick in the middle nor resistant. I sprayed underneath and above the door as i worked it back and fourth. I plan to change it out one day ($50-60 online).
Hi great video my Bmw is currently at a Bmw dealership for repairs the car does idles rough at low rpm' but when they rev it up till about 3500rpm the motor revs smoothly they already fitted new coil pack and plug wires new plugs and tips sensor lambda sensor they already tested my airflow meter by fitting a new one and their were no improvements do u maybe have any advice or information that could assist me please???!!!
my astra on idle its going up and down i clean the throttle body and the maf senzor but have the same problem i clen the egr valve and no solve the problem i opened the air flow meter and i cleaned with spray but astra doing the same what i need to do did i need to go right or left with the spring ?
Amazing! Before watching this I had 2% confidence that I could repair my AFM.. I have 99% now! Anyone know if 3vze (toyota 4runner) AFM is beyond the home repair man's tools/ability? I will probably open it up before anyone responds to wish me luck.
Hi 4diyers, i have a slight issue with my e30 '85 323i. I had a bad intake rubber hose and the car had too much air but it worked fine. Since i replaced it with new hose, rpms went up to about 1500. I tried to lower the rpms by turning the screw in the intake manifold on the passinger side and on the throttle body. I lowerd the rpms but the car lost power. Then i tried to move the teeth wheel in the amf counter clock wise and clock wise in order to get that air-fuel mix but i failed. Yesterday i moved the sweeper arm slighly to the left to gain some stable rpms and the car is still running poorly. Going uphill is a nightmare, almost impossible, and on a straight road rpms barrely go over 2000 rpms. Is there any way to improve my cars performance? Thanks and sorry for the long comment.
Start by checking the throttle position sensor and also look at the idle control valve. Those would be the two places to start for high idle. Don't forget to subscribe :)
You should have both, that is an M20 right??? I have a test for the throttle position sensor, I believe yours is the same as the M30 with a two stage switch. That was causing the high idle on my M30 when the idle circuit failed. The idle control valve can also stick, become dirty, or fail completely. Unfortunately I do not have a video on that as of yet. Another issue maybe a vacuum leak, either on the gaskets or any rubber hoses that deteriorate over time. Thank you for the support!
I have a 91 e30, starts and runs but when it’s still cold it fluctuates the revs from 500-700 until it’s warm basically. Don’t know if I should try to fix or leave alone. Excellent video man, we need more people like you.
Hi, thanks a lot for such an useful video like that, I was wondering if I can use that knowledge to fix my BMW 528e air flow meter? That air flow meter in your video is quite different from mine. Hope you answer me soon, and again thanks a lot.
+Adrián Mata Pineda Thank you. As long as it uses a flapper to monitor the air flow, then yes. I thought the air flow meter was the same on an E28. E28 body style right???
If you mean the black cap, there is a small amount of adhesive that will just break off once prying. Or if you mean the carbon track on the circuitboard, thats for the potentiometer which is just the conductor.
ok oks,sorry,i'm study english hehe,yes friend,the black cap,the other questions are solved,repeat,thanks for your time,big job,thanks for your wisdom,is very important for me learn for the future,and to part,love Bmw and learn thinks of bmw,for example,this caudalimeter,also goes to the Opel Calibra :) I suscribe with your channel,I follow you and i'm happy of speak you and understand,pracxtice the other language,open other or new vsion for me,I love :D
What about that hex screw on the outside of the afm box. I played w it by curiosity but I can't tell a difference gor the car was already normal tenperature. If you or anybody could give me some insight about how can this affect the performance of the car (1987 325i) Thanks
4DIYers ty it works it was a problem with the multimiter but when testing pin 2 &3 im getting 555 ohm when flap closed at middle highest value 900 ohms then it starts to decrease after 1/2open flap when fully open it has the minimum value 100 ohms that means I should replace my afm ?
I don't have maximum or minimum valves unfortunately. But it should be a fairy even value when it's closed or open. Here's a full testing tutorial which also shows how to test it using voltage. Using voltage is a much more reliable method than compared to resistance. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-hQYRep6K15k.html
Richer will increase performance, but not too much where it can flood out the engine. With a richer mixture, it will increase fuel consumption, foul up the plugs quicker, and you may risk plugging the catalytic converter.
hi, is that the maf sensor ( hot film mass airflow sensor, #1 on the diagram), or the throttle housing assembly next to #3 ? www.realoem.com/bmw/enUS/showparts?id=ET75-EUR-07-2004-E46-BMW-318i&diagId=13_0949
You can't just reduce the fuel economy by leaning out the fuel. A lean mixture won't allow the engine to run right, reduce performance and can burn out a valve or piston. The get the proper air/fuel ratio, the exhaust needs to be probed.
