ST200 Misfire!

[largerandrock]

Driving to work this morning and my ST started to run rough and now it sounds like its running on 3 maybe 4 well the easiest way to describe is it sounds like a scooby!
Any ideas what it could be ive made sure all the leads are in place and had a quick look but cant really see much as theres no bloody room! Would an air leak cause this or is it going to be spark?

[anonymous-user]

Superchipped? If so remove it. Next check the IMRC control-get someone to rev past 4K and you should see the linkage down in the lower inlet manifold move-common failure that usually causes lack of power but can cause rough runing if one of the gromets have broken and only half the secondary valves are opening.

[largerandrock]

Yeah that all works fine, think it must be a spark plug gone down or a lean/coil maybe

[Podie]

From what I've read on other forums, the coil is often the culprit. Not had the problem myself...

[anonymous-user]

OEM plugs & leads?

[Podie]

Jon GT2...

[ghosts_cloak]

I don't really know much about cars, but my uncle changed my spark plugs for me the other day in my 1.8 petrol focus, causing it to misfire. After lots of checking it turns out that the spark plug leads need to be VERY firmly connected to the plugs. He gave them a spray with some cleaning stuff and really clicked them into place, which seems to have solved the issue.
Gareth