shadow993

I got the misfire codes while driving in the rain. I have new plugs, caps, rotors, wires and belts.

I believe it's the belts, as I would get the the same code after washing the car.

My belts are OEM, look in good shape, and with the right amount of tension. The A/c belt is not oem.

Does anybody get this when their engine gets wet??

Any thoughts ??? Belts too loose ?? I believe I have the old pulleys. Although I don't know the difference.

HPNer

Hmmm, I have the same problem. I have new dizzies, coils and plugs. But I suspect the culprit is the ignition leads, so I'm going to change these shortly (no pun intended!).
I'm also a bit concerned regarding the various sensor connectors into the harness, I know some of these can corrode and cause some problems too (and not just in the wet).
I'll keep you posted.

pp000830

Old school says spray the ignition wires with WD40. It displaces the moisture. If it solves your problem you need new wires.

NYC993

I had really worn wires (sparking in dry) and old caps/rotors and no issues driving in rain.

Starting after overnght parking in rain is a different story, very rough idle, stalling, not able to restart for 15 min. Once hot and dry there were no issues. No CEL at all.

EDIT: Were the wires/caps/rotors intalled tightly?

shadow993

They popped and locked.

My gut is telling me that it has to do with the belts, as they are noisy at start up. Unfortunately belts don't have dates like tires, so you don't know how old they are when you buy them.

HPNer

I agree, I have no issues in the wet once driving, only the start after a good drenching.
WD40 only goes so far as the leads disappear into the boondocks of the engine, whereas water seems to get everywhere when the southwesterly blows.

NYC993

I have old belts (4-5 years) 27k miles that squeek sometimes. I'm not sure why belt would cause a misfire.

Any exposed wires? I make sure water doesn't get into other areas...frunk, under carpets, electric boxes in the back by the engine.

shadow993

Belts especially aftermarket belts have been known to cause CEL / P0300, based on my research on the forum. Also, DualMass Flywheel breaking up as well.

NYC993

So no misfire just a misfire CEL?

shadow993

CEL, but misfire codes. I however did not feel or hear any issues while driving.

NYC993

So replace the belts and let us know the outcome. You should be carrying a set of belts anyways.

shadow993

Will do.... I do, but aftermarkets that I picked up for emergencies. I toss the aftermarket belts out of the trunk every couple years. Cheap insurance.