A class misfire a150

[gaffy]

Hi all, having trouble with a class (w169 2005 a150 petrol) stalling at lights and bad misfire . Scanner said map sensor high pressure. New sensor no joy. Cleaned throttle body , new plugs ( one cylinder running rich). Better but not quite right, still not smooth but no engine warning light and no stalling. New coil pack on . Still same any ideas?? Thanks

 

[mbenz1]

Did you use a genuine MAF sensor? On MB cars, the engines seem to like OEM parts and not the cheaper aftermarket parts. If you've changed plugs and coil pack(s ?) then maybe check the condition of the leads that connect the plugs to the coil packs. - Corrosion, cracks and dirt etc...

In my car, the misfire symptoms were resolved with a new Bosch MAF and Coil Pack (Bosch was OEM back in the '90s - car is a 1998 320 petrol), hence the same principal should apply to your car.

Edit: it may be a good idea to clear codes after installing new parts, to get full effect

 

[grober]

This of any help - introductory text on the M266 engine -information on these is like hens teeth- I suggest you download it.
http://mycar.x431.com/dbscarImages/pdf/2013/06/04/6c047230-516b-4b71-a263-7d54f7cc2d75.pdf

 

[gaffy]

Thanks for link. There is little about on these engines. Are they mercedes designed or borrowed from another manufacturer ?

 

[gaffy]

Thanks for general advise . Wondered if there was issues particular to these cars??

 

[rhud]

It wasn't misfiring,but my first A Class (2007) was stalling at junctions. A software update at the dealers solved it.