Engine misfire

[Hammers 88]

Ive got a C240 W202. Had a misfre for about two months now. Garage said it was leads, changed them still misfiring. Then said it was one of the coil packs, changed that seemed ok for about two weeks. Now its come back again. Seems ok when cold once its warmed up idle is very rough and is down on power. Looked at other threads on the forum does this sound like the MAF is playing up, any help would be great as its driving me mad now thanks in advance.

 

[Miffy]

If you unplug the MAF, does it stay as bad, or worse? if its worse then skip the maf for now. have you had the fault codes read to see what cylinder is missing?

This happened to me, said fault was in No1, moved things about and moved the fault so had to be coil pack or leads, turned out to be 2 x new leads @ 25£ each lol

 

[Hammers 88]

Had a good fiddle around with the leads and the coil packs. When I pulled the lead off the new coil pack, there was no difference so it must be that one. Turned the engine off unplugged it all then put it back started the engine tickover was back to normal. Put the engine cover back on and it started misfiring again. Took it off made sure all the wires were secure and wouldnt touch the engine cover, put it back on and this time it didnt misfire. Hopefully it was just a wire getting pinched by the cover.