E30 Zone

Well it seems forever problems with my e30 335, heres my problem.

Drove through a big puddle a few days ago and the car started missfiring quite bad but eventually disappeared. I got the misfire again a slight bit one morning but cleared up again, the same day i noticed some of the ht leads were arching at the distributor cap (could see the spark) I thought this must be the problem so i borrowed the leads of my friends m20b25 engine. I noticed theres a 'cylinder id sensor' on the m30 engine lead to cylinder 6 (dont know exactly what this does or if its essential) but i just taped it to the m20 lead.

There is now no arching anywhere on the leads but somedays the missfire is so bad its almost undrivable and other days its still there but not too bad.

Before i go buy some m30 leads (£100 ) just wondered if anyone has any thoughs on what my problem could be.

Misfire could be many things I guess, though given you drove through a large puddle, I'd be cleaning and drying everything I could - coil, distributor cap, crank sensor (this would be my guess), I would check the air filter too just in case that got a soaking.

As an aside, the cylinder ID sensor on my M30 has not been connected for at least a year now and I have not noticed any negative symptoms or effects. I believe that the engine runs quite happily, but will use a little more fuel when this lead is disconnected.

Martin.