Another Misfire

[jarobinson25]

I hope someone can help me.
My C180K (manual) has started developing a misfire whilst idling. I'll be sitting at the lights and suddenly the engine will start shaking (as it goes from 4 cylinders to 3) and the engine warning light will come on. The problem is easily resolved by switching the engine off then on again, equally I can stop it from happening if I keep the revs up, but neither of these is really a long term solution.
The initial view from MB and my independant were that its probably the coil so yesterday my guy changed 3 of the coils (they didn't have 4 in stock) but this made no difference.
Would changing the 4th coil really make any difference?
My indy is now suggesting that it might be the ECU (my mate's new ECU cost him £600 so I'll avoid that if I can).
I've searched the forum but not found anything quite the same.
Any ideas folks?
Cheers

 

[BlackC55]

The sensitivity of the missfire detection can be adjusted on your engine.

When it missfires put a star on it and pick up which cylinder its coming from.

Its no good just bolting coils to it until its gone.

You may also have a cylinder head issue also. (poor sealing of the valves)

 

[jarobinson25]

Thanks BlackC55, I'll let my guy know when it next goes back in a couple of weeks.
Cheers