saiklon

I had the engine bay washed last week and since then I've had a severe intermittent misfire. My car uses the single coilpack on top of the manifold. When the misfire happens I can see sparks jumping from the top to the bottom part of the coils i.e. between the leads for 1 and 3 and between those of 2 and 4.

This morning it was especially bad so I removed the leads (which looked dry) and sprayed WD40 liberally everywhere, this fixed it till I parked the car for an hour.

Any ideas on what could be the cause and what else I can try to fix it?

EngineMapper @ Group B Motorsport

If you can see the spark jumping on the leads or the coil pack then it will be either of those that are causing the problem. One of the other common problem areas when you have pressure washed/steam cleaned under the bonnet is the two big engine loom plugs just behind the battery. They tend to corrode really easily. Unplugging them and spraying liberally with electrical contact cleaner.

Hope this helps,

Graham

saiklon

The spark seems to be jumping on the coil pack, however fiddling with the leads seems to fix it temporarily. I will give the coil another clean tonight and if that does not help I'll swap leads and coils with another car this weekend to test.

Yes, the two engine loom plugs gave me a headache one time. The car couldn't control idle till they were cleaned of corrosion. I'll clean them as well.

Thanks for the help.

saiklon

Update: In the absence of electrical contact cleaner, I used hot soapy water for the coil and leads and the engine loom plugs after which I dried them. All issues are now sorted.

Thanks for the help.