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Discussion Starter · #1 ·
Hello to all :) I'm KennygDownunder in North QLD State in Australia and this is my first post here so i hope i get the etiquette correct ! My Beast has been ailing , off and on for 3 years now but I couldn't get it to play up for my trusty mechanic. Finally it has decided to go on stike ( of sorts )......I cannot accelerate beyond about 3000/3500RMP even in Neutral ! Sometimes it goes normally like the true rocketship that it is and then other times " booing" it wont go ! I can drive as long as i remain in a higher gear and do not accelerate in a spirited manner. The codes appearing diagnostically were possible primary oxygen sensor(s) and LHS MAF ( in Australia we have RHD cars ) . I replaced BOTH primary oxygen sensors ( she has 90,000km on the odo and i presumed these needed replacing at this mileage ) and the LHS MAF...........now it is still doing the same ( if i take the LHS MAF off it runs wonderfully but that is the new one ! )......If I leave her for a week or so without cranking her up ( cold start ) or on a hot start after sitting say 10 minutes she starts fine then gets the jitters ( won't idle) and snuffs if i try to drive away. Fuel pump pressure is good. Any sage thoughts please as of course i cannot drive her and I live in rural North Queensland on the east coast ..........my very handy mechanic is pulling out what hair he has left and i am afraid he will lose all of his hair over my Beast ! Thanks in anticipation :)))))) Cheers all ....................KennygDownunder
 

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Discussion Starter · #5 ·
Yes both MAFS read on the diagnostic computer as functioning correctly. If I swap MAFS it still says there is an error on the LHS ( passenger side here ) MAF ?????
 

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Have you checked for vacuum leaks on the side that is reporting MAF problems? Any issues with the air filter box? If one of the air filters for some reason is much dirtier and clogged than the other, it could change the air flow to one side of the engine, thus triggering a MAF fault.
 

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Hi Kenny- Welcome.

Could you place a few "enters" into your posts??? :) Helps break up the parts that matter.

From the parts that don't

matter.

;)

When you say the MAFs are "new" is this "New BMW" or something else? Also, NEVER replace these one at a time- replace both.

When was the fuel filter replaced?

Replace both mafs, reset the adaptation and see how it goes. Your DME has gradually adapted to bad mafs, trying it's best to run OK with bad airflow data...but you've only replaced one and the DME takes these and combines the flow data to make an estimate of the air...when you replace just one the DME reallly has no good solution (gotta ask why someone thought that was a good idea, given all the posts here saying replace both)

Report back.

Have you done a MAF fuel flow test? More info inthe FAQ.

Also, and history on the plugs or CPS????
 

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Discussion Starter · #8 ·
MAF problems

Thank you Ard. I will take all that on board and take it to my mechanic . As i am new to the board I do not understand what you mean when you say I need to place " enters" in my posts ! S orry to be a dummy but i do want to comply with the rules here of course :)......Thanks Mate...............KennyG Downunder
 

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Discussion Starter · #9 ·
MAF Problems

Fulltone74..........Thanks for your reply. I do believe this has been checked ( I am running non standard filters....ummm I forget the names.....filterchargers ) The filters are both clean and no vacuum leak has been discovered. Fuel filter was replace 2 weeks ago ( i went there first )..............Thanks Mate.............KennyG Downunder :)
 

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Hey Kenny. Welcome!

There's your answer I bet- replace those oiled filters with stock and replace both MAFs. Over-oiling these filters kill MAFs fast.

Then try the "MAF" test in the FAQ section. It won't mean a lot unless you can get up near redline. You probably have other issues under dirty MAFs(probably including the new one at this point).

I'd also like to know your long term and short term fuel trims.

Good Luck,

dj

p.s. See how my thoughts are separated? That's what he meant by hitting "enter."
 

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Hello to all :) I'm KennygDownunder in North QLD State in Australia and this is my first post here so i hope i get the etiquette correct ! My Beast has been ailing , off and on for 3 years now but I couldn't get it to play up for my trusty mechanic. Finally it has decided to go on stike ( of sorts )......I cannot accelerate beyond about 3000/3500RMP even in Neutral ! Sometimes it goes normally like the true rocketship that it is and then other times " booing" it wont go ! I can drive as long as i remain in a higher gear and do not accelerate in a spirited manner. The codes appearing diagnostically were possible primary oxygen sensor(s) and LHS MAF ( in Australia we have RHD cars ) . I replaced BOTH primary oxygen sensors ( she has 90,000km on the odo and i presumed these needed replacing at this mileage ) and the LHS MAF...........now it is still doing the same ( if i take the LHS MAF off it runs wonderfully but that is the new one ! )......If I leave her for a week or so without cranking her up ( cold start ) or on a hot start after sitting say 10 minutes she starts fine then gets the jitters ( won't idle) and snuffs if i try to drive away. Fuel pump pressure is good. Any sage thoughts please as of course i cannot drive her and I live in rural North Queensland on the east coast ..........my very handy mechanic is pulling out what hair he has left and i am afraid he will lose all of his hair over my Beast ! Thanks in anticipation :)))))) Cheers all ....................KennygDownunder
So you are getting code 39, or 29 ? Or actually what code are you getting to suggest that you have a MAF failure.

If you are getting 39 (Bank 2 MAF iirc) when the MAF is actually physically plugged in ? Then I would have a very good look at the electrical connection of the MAF to your engine wiring loom, emphasis on your cars wiring at that connector.
 

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Discussion Starter · #12 ·
MAF Problems

Thank you Djazz ! You of course were correct. My trusty mechanic had inependantly found this forum and had been scouring it FAQ's as you suggest. A few minutes a go he rang me and told me to come get my Beast ! Once again I can travel safely at illegal speeds LOL. BOTH old MAF's had a fine coating of oil on them from my recently serviced K & N Filters ! I had experienced this problem once before with my E31 M70 ( 850Ci V12 ) and after reading all of the posts to me from you MOST helpful friends here on this forum I was beginning to suspect something " upline" of the MAF but hadn't recalled my experience with my old beautiful 850 ! YOU people here on this forum have been so courteous and helpful to me with my problem and as a newby here on the forum I am very impressed and grateful . I am a member of the Roadfly forum as well ( they have been very helpful too especially for my E31 ) . I am happy to have found a new bunch of car mad friends !:byebye:Cheers and Thanks Mate !...................KennyG Downunder
 

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Discussion Starter · #13 ·
Thank you DJazz I now know what the "enter" and separation issues mean :).........KennyGDownunder
 

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Glad we helped work it out. Usually comes down to some hidden detail that's staring you in the face. :biggrin: Happens to me all the time.

Take care,

dj
 
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