Hamster97

Active Member
I had a MAF go bad about 2500 miles ago which caused the engine to misbehave badly so I unplugged it and it ran fine....... for 2500 miles!
Anyway, I bit the bullet and bought a new genuine MAF and fitted it.
Problem now is it seems to be not getting enough fuel and has thrown system lean codes for both banks.
Has my ecu got used to running default settings and now needs to re learn how to run with a new MAF?
 
Best to clear faults, clear adaptions and see what happens....

Also Lean running could also be down to induction air leaks....chiefly either the PCV, Breathers or the actual intake manifold seals....which is more common than most realise!

To test this, using brake/carb cleaner, take the acoustic cover off and with the enigne running, spray it round the intake manifold to block joints, the PCV and the intake throttle body, any change in engine note means the spray is being sucked in due to an air leak.
 
I've cleared faults but no idea how to clear adaptions. Suppose I need a faultmate for that?
I'll get some carb cleaner and see what happens although the breathers and PCV were recently done so they should be Ok.
Cheers
 
Have a fire extinguisher to hand, probably me being a girl but I was quite nervous spraying my hot engine with rocket fuel :)
I cleared my adaptions with a faultmate but don't know any other way of doing it.
It took me a couple of goes to get the intake pipe on the throttle body without leaks
 
Mine runs a cone filter so that probably doesn't help for the intake pipe.
Screw the fire extinguisher, if it goes up, problem solved lol.
 
You can use the free EasyOBD software...works with a cheap ELM OBDII interface....and that will clear the fuel trims when you reset fault codes.....

It won't work with the All Comms....and I don't think All Comms clears fuel trims.
 
Thanks Saint, I've got inpa for my bmw so was going to try that.
The lean system faults have gone away now but been replaced with a Mass air sensor low input fault.
Gonna clean it with carb cleaner tomorrow and see how it goes.
HC, no mate, still tapping.
 
Update, decided the air meter was faulty so swapped for another, no codes and running normal.
Went out for a drive, went for an overtake and the gearbox kicked down, engine went into failsafe mode. Read the codes and it's there again, Mass air flow, low input.
Any ideas?
P. S. Saint, couldn't get inpa to work, did you ever get yours connected?
 
Last edited:
No other codes at all just the low input, o2 sensors ok, electrical thermostat ok ?
Reset and try again, maybe it will start to learn the new mixture... i am clutching at straws but have a search using the x5 term or m62, quite a bit of bimmer info. That filter probably doesn't help.
 
I've got a camshaft advanced code on bank 1 because the garage didn't re check the vanos after 2 turns but that's in hand and is mechanical so would that cause the airflow meter to shat itself?
Besides that, no other codes and I wondered about the filter but it's been fine for the last 20,000 miles.
I'm just a bit worried that it's done another air flow meter, auto factors probably wouldn't accept it back and claim I've got an issue that caused the part to fail so it's probably in my best interest to try and find out if I do have an issue which is breaking air flow meters.
Cheers mate
 
What air MAF did you buy, think OEM is Bosch , I've heard bad things about non OEM.
Not sure about the vanos error, has it been running ok since the rebuild up until now ?
All wiring ok to the MAF and have you tried unplugging it again and driving it?
 
New Bosch MAF, original MAF shat itself a couple of days after I got it back and been running with it unplugged since until yesterday.
The new one was fine and lasted a few miles no probs till I went for an overtake, it kicked down and went into engine failsafe mode and gave me the P0102 code.
 
Update, decided the air meter was faulty so swapped for another, no codes and running normal.
Went out for a drive, went for an overtake and the gearbox kicked down, engine went into failsafe mode. Read the codes and it's there again, Mass air flow, low input.
Any ideas?
P. S. Saint, couldn't get inpa to work, did you ever get yours connected?
I had no luck with INPA nor NavCoder.....you need vehicle specific config files and I couldn't find any....although I do know they exist.

Odd you have issues with both MAFs....they are stupidly simple things so doubt something in the car is breaking them....only way that could happen is if there is a short in the wiring giving it voltages it is not designed for!

I'd be tempted to try your 'duff' MAF on another L322 and see if the symptoms persist on the second car, this will prove the MAF one way or other.

Also, I'd be looking to open up the E-Box and look at the ECU connections for signs of corrosion or looseness....they can suffer from water tracking along the loom and into the E-Box.

Get a cheap ELM OBDii interface (can be had off Amazon or similar for less than a tenner!) and using a free OBDii program, read the airflow readings and ensure they rise and fall accordingly.....

If you want to go down that route, I can upload a video of my readings so you can compare.
 
Sorry lads, been away for a week and went in the Range Rover. It's just completed a 400 mile round trip from Derby to Lowestoft average 60mph and got 16mpg on LPG. There's so many things wrong that need sorting before I start complaining about a lack of power or poor MPG I know but if something throws a code, it's faulty although a bad MAF is probably the least of my problems lol.

Can you clear the code and try again, will it start and run ok?
Yes it runs fine mate, code came back more or less straight away but it runs and drives fine considering the other problems it has.
Odd you have issues with both MAFs....they are stupidly simple things so doubt something in the car is breaking them....only way that could happen is if there is a short in the wiring giving it voltages it is not designed for!

I'd be tempted to try your 'duff' MAF on another L322 and see if the symptoms persist on the second car, this will prove the MAF one way or other.

Also, I'd be looking to open up the E-Box and look at the ECU connections for signs of corrosion or looseness....they can suffer from water tracking along the loom and into the E-Box.

Get a cheap ELM OBDii interface (can be had off Amazon or similar for less than a tenner!) and using a free OBDii program, read the airflow readings and ensure they rise and fall accordingly.....

If you want to go down that route, I can upload a video of my readings so you can compare.
Cheers mate, new MAF was fine with no codes and the engine did seem slightly better for all of about 10 minutes until it gave up after the attempted overtake.
I've got a cheap Bluetooth adapter and torque pro which give me some live readings so some idea of what I should be looking for would be a big help.
Would spraying WD40 in the plugs and connections in the e box help? MOT next week but it should be fine on emissions cos it gets tested running on LPG.
Thanks
 
Last edited:
Will do a vid for you to compare..

WD40 is not a good electrical cleaner. A good electrical contact cleaner would be best can be had from the likes of Maplins etc.

If the CEL lamp is lit, that is an MOT fail off the bat regardless of emissions results as far as I know.
 
Will do a vid for you to compare..

WD40 is not a good electrical cleaner. A good electrical contact cleaner would be best can be had from the likes of Maplins etc.

If the CEL lamp is lit, that is an MOT fail off the bat regardless of emissions results as far as I know.
Think it's only an advise Ant, ABS lamp lit is a fail.
 
I had s search for vanos and the code you have and a few threads came back so I wonder if the timing being out is a problem or if somehow the vanos work carried out has caused the problem.
This is worth a read about loose earth

http://www.e90post.com/forums/showthread.php?t=755215

Air leaks cropped up a few times again and pumping the brake caused the idle to change on one thread.
Have a search for vanos seals and your code or MAF
 
Cheers lads, I need to get my arse in gear now and get it finished, the timing and the lifters can be done now I've had my holiday and can manage without the car for a little while.
I've noticed some oil underneath now as well which seems to be coming from a bodged oil separator and I've seen some posts mention that an oil separator can give a p0102 code if it's drawing air so that's another for the list.
P.S. There's no lights on the dash so fingers crossed for the test.
Thanks all.
 

Similar threads