I've recently found myself in the market for a new MAF for my 1991 850i. The dealer pricing makes a BMW/Bosch unit unrealistic. After searching the forum it appears that the majority of 'new' MAFs out there (ebay, amazon, etc) are junk. The consensus seems to be that the Cardone's units, however, are a reasonable alternative as they provide OE functionality (hot wire, same response curve). I started tracking down a Cardone unit.
This may not be news to some, but it turns out they are back ordered, with both brick and mortar and most websites unable to provide an ETA. According to Summit Racing, they are back ordered to July 15, although this date increases each day. I reached out to Cardone directly, and unsurprisingly, their production lines are shutdown for the foreseeable future. However, the good news is that Cardone will still be producing them, and they will be available. At some point.
Hopefully someone in the same position as me finds this info helpful as we approach the driving season.
Last edited by DeltaSix; 04-17-2020 at 11:57 AM.
Try Rockauto for the Walker brand: http://www.walkerproducts.com/wp-con...AF_Catalog.pdf
https://www.rockauto.com/en/parts/wa...ow+sensor,5128 ~$120, best price.
Amazon has them too, but ~$135
'91 Dinan 860 Stage III (new 6L engine)
'91 Dinan 850 TT stage III (brand new engine) 21st Century Tech meets 18th Century Dinan...
'91 850i 6sp (mint) (sold)
'90 Dinan 750iL TT stage III (Guido - The Beast)
'94 850 CSi The Detroit Auto Show car (restored to factory perfect) (sold)
'96 850Ci, The George Carlin car
''73 3.0 csi, '08 535i, '03 X5 4.6is
...and a few other non BMW cars
Are the Walker 245-1208 really good for the M70? I just read this thread about Walker on the M70 and the comments by dragon850: New MAF Sensors but still having Trans Failsafe Mode https://www.bimmerforums.com/forum/s...-Failsafe-Mode
@JDP530: you installed the Walker MAF's 2 years ago, so there should be sufficient experience by now.
Shogun tricks and tips for the E32 series are HERE!
Yes, I did install them on my car and they seemed to perform pretty well. Occasionally it would hunt for a steady idle with cold startup. Fitment was fine, housings were almost identical, and plug receptacles were the same as the OEM. I didn't leave them on very long because they did not solve the issues I was having with my car. My car is down right now also because I'm waiting on another auto transmission to put in it. I meant to send the Walker sensors out to cartoonz and let him evaluate them but I never did.
I have the Walker set on my 850. They seem to work fine, I also have the Intermittent LHM that will go away if I back off and get back into throttle. The ones on my car were dead, these made it run better but not perfect. My Opionion is that I still have DK Throttle body potentionmer issues
I’ve had the WALKER MAFS on my car for the last 8/9 years and no problems.
'93 850Ci - Mineralweiß Metallic
2001 740iL - Titansilber
ALPINA B7 -Alpinweiß III
...the price of cool ain't cheap!
Thanks for all the replies. Wow, wasn’t expecting such a response. Seems to be a hot topic!
I’m going to give the walkers a try but I’ve also put in an order for the Cardone MAFs. I am curious what the difference will be, if or when the Cardone units become available.
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Last edited by DeltaSix; 04-18-2020 at 02:04 PM.
DeltaSix- are you part of our BC Eights group ......? Wuffer is the contact if you are not on our roster. No dues, just WrenchFests, some driving events, the annual German Car Festival at Waterfront Park in North Van. Our little group puts out a newsletter from time to time.
HenryC- in Tsawwassen
Hey Henry, thanks for thinking of that. I already am in fact. You and I actually met at Wuffer’s a couple of years ago. I think you were pulling a CSI bumper off of one of Wuffer’s parts cars.
Work kept me busy last wrenchfest season but I’ll definitely have to hop the pod this year.
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Is your E31 Laguna Green?
Some old Maf info:
If any need just a used replacement Maf, You can get from the 24 cars listed below,
Now the 850 owners may be able to get some more power using a combination of Bored out throttle body + Higher Flow MAF from the BMW E36 325i. Yes it may benefit from ECU programming to optimize the AF mixture. Can be installed in one afternoon with simple hand tools and completely reversible in about the same time.
Also, 19Lb injectors in place of the stock 14 lb injectors. MAF sensor from 92 325i(pre Sep,92), 3" ID versus 850i stock MAF sensor which is 2 5/8" ID. This combination alone will support 420 HP(6 PSI) without any other mods, Factory motronics will handle since effectively the injectors and MAF are matched. A cartech FMU will handle fuel needs beyond 420 HP.
BMW MASS AIR FLOW METER SENSOR MAF 318 750 850 Z3 92-98
Brand BMW Mass Air Flow Sensor Meter
BMW # 13621736224
BOSCH # 0280217110 , 0 280 217 110
This part is compatible with 24 vehicle(s).
Year Make and Model Type Engine
1996-1998 BMW 318I E36 1.9L
1993-1995 BMW 318IC E36 1.8L
1996-1998 BMW 318IC E36 1.9L
1996-1997 BMW 318IS E36 1.9L
1995 BMW 318TI E36 1.8L
1996-1999 BMW 318TI E36 1.9L
1995-2001 BMW 750IL E36 5.4L
1995-1997 BMW 850CI E31 5.4L
1992 BMW 850I E31 5.0L
1995-1998 BMW Z3 ROADSTER 1.9L
Year Make Model Trim Engine Notes
1995 BMW 318ti All All
1995 BMW 750iL All All
1995 BMW 850Ci All All
1992 BMW 850i All All
Year Make Model Trim Engine Notes
2001 BMW 750iL All All
2000 BMW 750iL All All
1999 BMW 318ti All All
1999 BMW 750iL All All
1998 BMW 318i All All
1998 BMW 318ti All All
1998 BMW 750iL All All
1998 BMW Z3 All All
1997 BMW 318i All All
So now you can get some spares at your local salvage yard,)
Based on recommendations above just got these Walker MAF’s. Will test them over the weekend and report back.
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91 850i 6-speed, 2018 M550 - wife mobile, Lexus GX460 - Family mobile
Ok, so these Walker MAF’s are a no go for me. The engine wasn’t idling properly with these and the CEL came on within a minute. Read the error code - pointed to O2 sensor. I also felt the engine was running too rich. I cleared the code and tried again - same result.
BTW - I have brand new O2 sensors installed. So they are definitely not a problem.
I was looking to install a new MAF to address loss of throttle when the engine is cold but looks like another round of cleaning the original MAF’s with a detergent (just kidding - used a MAF cleaner) might have done the trick .
So needless to say these MAF’s need to “walk” back to RockAuto.
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91 850i 6-speed, 2018 M550 - wife mobile, Lexus GX460 - Family mobile
I gave the Walker MAFs a go as well the past week. My initial experience was the same as akatock: CEL + o2 codes in DIS
However, I thought perhaps the fuel trimming might be way off from the previous set of MAFs and was the cause of the CEL. I decided to allow some time for the computer to adjust to its new inputs.
After a week of driving, perhaps 200km, I can happily report that I am no longer seeing a CEL and drivability has been restored to when I had working MAFs previously—subjectively better, in fact.
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Akatoch - I examined your photo quite closely of the MAF's on your workbench. Looks like you received the French MAF units for the E31, which operate metrically, or French ohms as they say in Renault product development. This is most likely the reason for the CEL being set off on your E31 USA production version. One only needs to flip the switch on the under side of these French metric MAF units to have them function imperially rather than metrically, thus communicating with your USA version E31 electronics. These French MAF units would be perfectly happy on E31's originally shipped to French speaking Quebec Canada. Hope this helps.
OK......- Ha ha....just a little humor/ Henry
when replacing MAFs, it is always a good idea to do a hard reset. (disconnect batteries)
This resets all adaptations and base values.
..and Henry, he is lucky he did not get the Portuguese versions!
'91 Dinan 860 Stage III (new 6L engine)
'91 Dinan 850 TT stage III (brand new engine) 21st Century Tech meets 18th Century Dinan...
'91 850i 6sp (mint) (sold)
'90 Dinan 750iL TT stage III (Guido - The Beast)
'94 850 CSi The Detroit Auto Show car (restored to factory perfect) (sold)
'96 850Ci, The George Carlin car
''73 3.0 csi, '08 535i, '03 X5 4.6is
...and a few other non BMW cars
A little humor never hurts, considering these cars joke with our brains and wallets all the time .
But I haven’t shipped those MAF’s back yet - I might try the battery disconnect method.
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91 850i 6-speed, 2018 M550 - wife mobile, Lexus GX460 - Family mobile
Cartoonz- Right On, regarding the Portuguese version MAF's.
Also a good tip re the hard reset.
Ok “magic reset” didn’t help with the Walker MAF’s either. So they are definitely going back.
Anyone have recommendations for alternatives?
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91 850i 6-speed, 2018 M550 - wife mobile, Lexus GX460 - Family mobile
Akatoch asked me last weekend about whether the car seemed rich at idle with the Walker MAFs. I finally got around to checking my adaptation values and wanted to post the results and some research/thoughts about my findings. I should preface this with the fact that the Walkers are working fine out of the box for me. Although the adaptations did need to be adjusted (automatically by the ECUs) before my CEL cleared.
Before I swapped in the Walkers I had recorded my Idle and Partial Load trims as:
Cyl 1-6 Cyl 7-12
LL: 14 LL:20
TL: 4 TL:-26
With the Walker MAFs these values are now:
Cyl 1-6 Cyl 7-12
LL: 127 LL:65
TL: -18 TL:-21
The partial load trims look fine. More or less in the middle of the adaptation range. However, the idle trim of 127 on a Cyl 1-6 gave me pause since that is suspiciously exact to the max value for a signed 8-bit integer. It seems reasonable, based on the age of the car and its electronics, that there is an 8-bit register for fuel trim and that value is currenlty maxed out. I don't have a CEL, but there isn't much room for variation if the value is already maxed out. I decided to look into why this might be.
With a simple replacement of MAFs, what could cause such a drastic difference in the fuel trims between pre- and post-replacement? The first posibility is that the Walker MAFs are not a correct for the M70 engine. Aftermarket parts are always suspect, so a very reasonable proposition.
However, I came across this page on the e31 repair guide: http://e31repair.com/en/repair/htm/0185.html
Bottom right, step 3: "CO Level Correction. Remove anti-tamper lock. Correct CO setting on mass sensor with screwdriver, if necessary".
Ah ha! So that's what the screw on the Walkers is for. This leads to the second posibility: MAFs need to be calibrated to your specific engine, or at least "dialed in". Walker MAFs just "helpfully" don't have a tamper plug on the screw.
I came across this post from 2010 https://www.bimmerforums.com/forum/s...justment-screw that indicates this is something people have noticed before.
There is also this post from the e30 forums that goes into an indepth explanation on how to adjust the trim on the MAF, if you don't have DIS or a CO sensor (it involves tapping into the O2 sensor voltage while you adjust the MAF). https://www.bimmerforums.com/forum/showthread.php?1339369-AFM-air-screw-adjustment&p=17827272#post17827272
The long and short of my interpretation of all this: New MAFs likely need to be adjusted. If they are not adjusted properly the O2 voltage at Idle can potentially be too rich or too lean, causing a CEL. Generally, for most people, it seems that they are set at the factory in such a way that the MAFs don't cause a CEL. I should also point out that before adjusting your MAF you must be 100% certain that there is no unmetered air getting into the engine, and that the FPRs are functioning correctly. Basically, don't think adjusting the MAF will be a cure for other issues.
I certainly dont have a CO mixture probe, but I do have access to DIS. My next plan is to use DIS to monitor the LL, TL and O2 voltage such that the trims are closer to 0 at idle (at least not -128 or 127) AND confirm that the O2 voltage fluctuates, rather than be pinned at one Vmax or the other.
Last edited by DeltaSix; 05-17-2020 at 02:10 PM.
Wow thanks for the detailed post! I will try to install them again, one MAF at a time and play around with the adjustment screw to see if I am able to stabilize the idle and smooth out the throttle response.
Today's trial run stunk up the entire area around the house with gasoline and exhaust and the family wasn't pleased with the situation , next time I do this I will go to an open playground .
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91 850i 6-speed, 2018 M550 - wife mobile, Lexus GX460 - Family mobile
This adjusting screw is not for mixture adjustment in oxygen sensor controlled engines:
MAF.jpg
The pin is not even connected.
It will only work for systems without oxygen sensor / catalyst.
Here is some more information to this MAF topic:
1.)
https://www.bimmerforums.com/forum/s...or-M70-Engines
2.) You can change the language in the menu:
https://www.8er.info/der-luftmassenm...m-8er-bmw-e31/
3.)
http://www.8er.org/forum/showthread.php?17051
Last edited by black850i DE; 05-18-2020 at 07:49 AM.
Regards
Johannes
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