Thought on MAF sensor

[DrNick]

With all this discussion of MAF sensors, I'm wondering if its possible ( or sensible) to modify the output to modify performance. I'm thinking that applying a small amount of gain to the output voltage should indicate to the ECU that lots of air is flowing and so it will be fooled into increasing the turbo boost/ fuelling (on my old turbo diesel)

As the output is on a 0 to 5V scale this should be a relatively easy thing to achieve.

Anybody got any comments, or can explain in more detail of how the MAF fits into the overall management strategy of an old turbo diesel?

 

[jgevers]

Hi,

Yes it is possible to use a faster progression of voltage and get more fuel/boost. The boost shoots past it's target pressure for a few seconds. After this the ECU will regulate the boost to normal levels through the control solenoid. In my experience the held boost seems to be about 0.1/0.2 bar higher as well. A bit more smoke is produced though. The drawback can be that the exhaust gas temperature gets a bit to high which in turn wears turbos out a bit faster. It did in my Golf Tdi anyway.............

The cheapest way to do this is to change the MAF for another. The most suitable is a VAG petrol engine one. The element will fit directly in the MB housing and the plug will fit. I can't remember the Bosch part no. but it ends in 002. About £50.

When you change the turbo for a much bigger one you will get blowback that makes the MAF produce some silly spikes at the wrong time. For this I use a programmable box to produce a predicted air mass voltage so that I don't need to run a MAF. For this you do need rev. signal, TPPS signal and MAP voltage though.

regards,

Job

 

[No1vic]

MAF DIY repair maybe?

Just a thought after reading this thread. Would it be possible to compile a MAF element Bosch part number to Mercedes MAF unit compatability table. How many on here could do with a new MAF unit, certainly £50 is more acceptable than the £250+ usually quoted for replacements especially when the only 'faulty' part is the element and not the whole unit.

 

[jgevers]

Hi,

What I am about to say is technically incorrect and goes against repair policies from parts manufacturers and vehicle manufacturers. On top of that, for some applications it does not work correctly.

Most diesel MAF sensors elements can be replaced by one of two parts. A VAG Bosch sensor and a MB Pierburg sensor. Both approx. £50.

With petrol engines it is more tricky. Providing the plug is rectangular with one rounded end, most vehicles will run correctly with one of 3 Bosch sensor elements. However, this is not definate, and determining which element is needed normally results in trial and error. All 3 sensors approx. £50-60.

In order to compile a list, it would take a fair few people to remove the element from their sensor body which is fitted with security Torx20 on earlier models and security star on later models.

I would expect that most people prefer their local friendly independent garage who carry a lot of MAFs in stock to determine which one is needed?

Regards,

Job

Just a thought after reading this thread. Would it be possible to compile a MAF element Bosch part number to Mercedes MAF unit compatability table. How many on here could do with a new MAF unit, certainly £50 is more acceptable than the £250+ usually quoted for replacements especially when the only 'faulty' part is the element and not the whole unit.

 

[silverarrow]

have a look at www.bba-reman.com :bannana: