can anyone help

[nick1shaw]

hi can anyone help please.
my wife has a clk200 and it has developed a bad misfire. i have changed a coil pack checked the ht leads and it is still doing it. i took it and had it put on the diagnostics but no fault showed up.some people have said the ecu's play up on these also the wiring loom may be to blame. i have noticed that there are a few knowlagable people here and wondered if anyone could help please.

 

[BlackC55]

Try swapping the coil's rubber cap with the other cylinder and see if the missfire jumps.

It really needs to be looked at with a machine that reads live data.

 

[BlackC55]

Oh and do a compression check.

 

[nick1shaw]

hi i have changed the coil packs from back to front and made no diff,
i was wondering if it could need a set of ht leads? would that show on the diagnostics?? but thank you for your help so far