I've had this problem 3 times, and ONLY when it's been raining. When I get off the highway, it starts to spit and sputter, and eventually throw P0300-Random Misfire.
The first time it happened, was way before the hood vents, so I have to rule that out. The last two times were just recently, including today.
The weird thing is, that when I went out to bring it in the shop today to dry out a little, it started up and ran fine. WTF?

 

Wrong forum buddy. This is for R56 problems (2007+)

 

Sorry. Maybe one of the admin's can move it.

 

Thanks Dave!

 

Just cleared the code, it was P0303-Number 3 cyl misfire. I think i'm going try a different set of wires.

 

spray the engine with a "spray bottle" and water and see if the misfire happens. if it does see if replacing the wires helps or it may be a cracked dizzy. good luck!

 

A cracked dizzy? What the hell is that?

 

Try to check the coil... I believe that you have a Screamin' Demon from your sig and I read in some thread about a member with a similar problem and was caused by that part. Wires and overall fitting are good way to go too.

Good luck on fixing your problem

 

Thanks man, i'll check that. I'll try to get a stock coil tomorrow and plug it in.

 

dude ; don't do the wires unless you got them hangin' around. i had the same crap happinin' and i put the old wires back on ; then the old plugs; then i said to hell and put the old coil pack back on.... bingo!!!! my sreamin' deamon had crapped the bed. !!!

 

Was it all the time, herbie? or just when it was raining?

 

Have you pulled the #3 plug to see if it has any shorted burn marks or damage? It might indicate that you have a plug boot leaking water onto the top of the plug.

You might want to pull all of the plugs and make sure each has a good coating of dielectirc grease on the plug top and then put a bit of it on the boot to seal out any water.

 

I will be checking them all tomorrow. The car ran perfect on the way home. No rain.

You have Kingsborne wires, you notice where the wire comes out of the boot? There is a good gap right there where the wire bends away from the boot for water to sit in.

I had put dielectric grease in both boots when I installed them, but that was a while ago. Thanks for the post.

 

mine would happen if it sat for more than a day or in the rain it was more frequent . if i feathered the throttle i could get to where i was going . but if i jumped on the throttle at all it would severely break up . w-d 40 didn't help . but it may for you . spray it on the connector to the coil and the wires. (water displacement - formula 40 ) .