Hi,
I am new to this forum and hoping that you guys can help me out please. So I bought a 2003 C 180 Kompressor just before Xmas and was really looking forward to owning my first Merc. SO shortly after getting the car it developed a problem whereas it was struggling under load and appeared to be hunting. I had been told that the car had been stood for a couple of years, so my first point of call was to fill it up with premium grade fuel and take it for a couple of long runs. Three full tanks later, the problem was still there. So changed plugs, replaced a couple of suspect coil packs. Still didn’t cure the problem.
Then checked for hose leaks - all ok. Then started looking at the MAF and replaced it with a new one from Magneti Marelli and still the problem is there.
Interestingly the new MAF, although it is supposed to be for this car, has an additional component inside which appears to be like a “black coloured” capacitor soldered to a couple of the pins in the MAF. This component is not there on the original MAF that I took out of the car!
I have connected a Konnwei scanner and it shows up no error codes. I suspect that, as this is not a bespoke MB diagnostic scanner then it probably is not able to pick up subtle errors that the MB scanner would do.

So I am praying that some one here can shed some light and a solution. Also if there is someone with a MB scanner near Chepstow, UK that could help me please?
Many thanks .

 

Fuel supply perhaps? Have you checked the fuel pressure? It it’s been sitting, bad petrol may have contaminated the filter.

 

the fuel filter has been changed and my suspicions are now on the fuel pump.