MAF/MAS/ The air thing

[Thmsshaun]

MAF/MAS/ The air thing????

How much of a difference should there be in performance with this device connected and disconnected?

Thanks.

Oh the reason I ask is that I cant tell any difference

 

[Thmsshaun]

£280 Inc VAT from MB of Derby does that sound about right?


Anyone know if the ECU would need to be reset or is it just a case of plug and play?

 

[1998K]

Anyone know if the ECU would need to be reset or is it just a case of plug and play?

as far as I know, as I asked to the technician who have done the jobe on my '98 W202, it's not requested any ecu reset

if I have to change my again (really I hope no! ) I'll do it by myself, it's an easy plug and play!

hi

Marco

 

[w124coupe]

If you can't tell any difference then the MAF either hard-failed or is perfectly OK.

Its job is to help the ECU fine tune fuelling by compensating for air density changes (temp and/or altitude).

On a 20c day at sea level it does not a lot!

If it hard fails (no output signal) the ECU uses a default map just like if you disconnect it - it does, however, set a fault code.

 

[Thmsshaun]

Was not happy earlier! Hope it is partly to do with the MAF and the fact the oter Car was very very highly tuned but a fiesta van had me up to 100!!! My god it was a fast little car.

 

[1998K]

as per my experience, when my MAS went out, I couldn't rev. over 1000rpm! car couldn't move!

in any case if you doubt thatìs the MAS, go to check the ECU to a mechanic!

hi

 

[W L Ow]

In the case of my C200 w202A, the car knock or pinked (engine gives out loud, rapid rattle sound) during acceleration or climbing slopes when the MAF was disconnected because it was faulty. The knock or pink disappeared completely after a new MAF was fitted.

 

[Glenn Smith]

How much of a difference should there be in performance with this device connected and disconnected?

Thanks.

Oh the reason I ask is that I cant tell any difference

Depends on the engine, diesels are usually less effected than petrols, some of the vw diesels i've worked on ran better with them disconnected, and no faults are recorded, fit a new one and they flew.
on a petrol engine they play a very large part in the calculations to provide correct fuel air ratio, this is less important to the diesel engine.
I would say yours is faulty.

 

[Stratman]

The engine will run reasonably well without a MAF. The ECU will use the 'default' programme for air/fuel vs revs vs load and make a decent job of it. The MAF provides 'fine tuning' information to the ECU about the volume and temperature of the air entering the engine so it can tweak the mixture and attain lower emissions.

Incidentally, when the boy racers have their ECUs 'chipped' for higher performance it is the default programme that is replaced by the chip.