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525D New MAF , still problem.

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Hi, new MAF fitted - does it need any "setting up" with INPA??

The story so far - eventually got around to fitting 6 glowplugs, engine breather, air filter, removed swirl flaps and cleaned EGR & inlet and fitted new MAF.

I still have the hesitancy / delay on accelleration, resorting to manual select 1st, left foot brake , rev engine & release brake at road junctions.

EGR - used hand vac pump to check diaphragm & operation. Fitted new vac pipe from EGR to valve to vac manifold.

Blanked vac outlet on manifold for swirl flaps but left solenoid in place with inlets blanked.

 

Read as many threads on here and elsewhere re problem. Now running with MAF unplugged, seems pretty much perfect , so new MAF faulty?? which would be a ...... as bought from Autodoc - did not realise they are in Germany until after order placed.

Can the MAF be checked with multimeter / does it need setting in INPA - if so , how?

 

Anything I have missed??

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Tried cleaning using isopropyl alcohol / pcb cleaner.  No difference , hence bought new. Just looked at box for new MAF - made by Johns. several other posters have said only trust Bosch units.

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..hmm to ensure that its a defo mafs fault the best would be to hook up working one from another bmw. would you have someone around which is willing to help?

 

Sent from my SM-N910F using Tapatalk

 

 

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not sure how to do it with inpa, if anyone can advise please outline process.Used the reset maf adapatations on a Launch diognostic machine before but no longer have access :(

 

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I cleared DDE5 module error codes when fitted all parts. Code 4501 came back after a short drive ( EGR neg deviation or air mass too high). Cleared this & blanked off vac pipe to EGR, no real difference to drive/ still hesitates on low rev acceleration so reinstated EGR operation. Checked for fault , showing 3FF0 - airflow meter. Unable to read any other text as in German!! Cleared & now running with MAF disconnected - seems to drive ok  except for EML on , need to check what code it is. Have ordered today a Bosch MAF & will update after fitting.

I also have PDC fault due to faulty reverse sensor.  CD has not worked for some time since had really hot day, now CD on idrive is "oranged out"- not sure where to start on that problem until BMW tools 2.12  better sorted (running Win 10).

Will error codes on different module affect other modules??

 

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New Bosch MAF fitted  and  error message (3FF0) cleared.  Cannot feel any difference - still hesitates / no low down power , so back to MAF disconnected and accept the low mpg to make the car drivable.

I am also watching newer thread by Jinsta whose problem seems similar.

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Without the MAF the car the estimates the incoming airflow so unplugging it is masking the real problem. A tiny split or leak in the vacuum system means the DDE is setting an actuator to a position but the airflow isn't as expected. The car will drive badly. A split of the intake hoses, the huge 3" or 4" stuff from the air cleaner through the intercooler to the EGR, will have the same effect. The DDE can see that the values it is getting supplied don't add up and deduces the MAF is the fault.

 

On my car I've seen a faulty pressure converter, a blocked vacuum hose and vacuum leak where a T had a tiny crack. All caused terrible driveability issues. I have a lovely new spare Bosch MAF to prove it....

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Thanks for info. I have used hand vac pump to check egr diaphragm. Also fitted vacpump& gauge to egr pipe from solenoid valve / pressure converter.- shows vac pulsing down to around 20"hg and rising when engine running. 

If I connect vac gauge to one of the two spare blanked tappings , what sort of reading should I expect & how long should it maintain when engine stopped???  Anyone know ??  

I did consider turbo vanes / actuator faulty but then fault would stay when maf disconnected ??

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I know the 535d very well but not the 525d. On the 535d the vacuum T has something like 5 taps. The taps have a 1mm dia or 0.5mm dia hole to control the vacuum split. The exhaust tip flap, engine mounts, swirl flaps, brake servo, EGR, wastegate and 2 or 3 turbo actuators are controlled by vacuum. A leak anywhere can upset the system. I had to isolate and check the whole system. With the engine stopped the vacuum on mine probably holds the actuators for about 10s then I hear them let go. The brake servo has it's own non return valve and that keeps the pedal assistance for a couple of days.

 

I found it best to check the vac system with the engine off. On mine the intake manifold needs to come off to access most of the vac system anyway. I was looking for actuation and holding a vacuum.

 

The 0.5mm hole in the T blocked so I used another T.

 

Some people have had actuators fail but that's rare. Pressure Converters do fail quite a lot.

 

You've changed the MAP sensor but that can get blocked.

 

Separate to the vac system a split on the air intake pipe from the intercooler to EGR is not uncommon.

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Faults on other modules won't affect the DDE.

 

Your fault code air mass to high is saying the DDE thinks there's a leak after the MAF. That can be an air leak or a vac problem.

 

On the MAF I think I remember there are two types one has an extra couple of connections for an air temp sensor. Worth checking your replacement is correct or it will seem faulty to the DDE but I think you'll get a specific error code for this.

 

Despite all of the above is your exhaust manifold leaking? That can cause a terrible acceleration lag.

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Interesting how MAF differs from vehicles. My boys Seat Leon 1.9 TDi had no go what-so-ever just about made 30mph. Replaced MAF car is back to normal.

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