Infuriating missfire

[mattjbatch]

How do.

My 318iS is being a bugger. It developed a slight misfire a few weeks ago. Its gradually got slghtly worse. This occurs almost all the time except when absolutely cold. After 1 minute of driving it kicks in. On very very light throttle it doesn't happen but as soon as a bit of right foot gets involved it reverts to 3 cylinder mode. All the vacuum hoses have been refreshed and the temp sensors replaced. Any help/comments/ideas/stabs in the dark much appreciated as this is doing my nut in.

Matt

[cheesebox]

I had this on my 318iS and it turned out to be a poor contact on a connector to the fuel injection plug board - under the inlet manifold, just above the starter. Let me know if a picture would help.

[mattjbatch]

Hi mate, A picture would be most welcome. I'll pm you my email.

Cheers
Matt

[cheesebox]

Matt

Here's the beastie in question:


It's tipping it down, as you can see!

Just re-seating this connector was enough to cure mine, though you might find you need to clean the contacts depending how bad they are.

This is just one of several possible causes of misfire, I think there's been quite a few threads on the subject. Anyway, hope you get it sorted quickly mate.

Cheers

Piers

[mattjbatch]

Cheers for that Piers, much appreciated.