Not that my Camaro sees the rain really, but when it does I experience a misfire where the motor doesn't want to act properly until it reaches about 3000 rpms. For the record, I've tested all the coils, and have new spark plugs and wires (these later two done twice). Do I have a sensor that is getting wet and messing things up? Could my O2 simulator not be sealing right and causing misfire in the rain?
Thanks!

 

Your optispark or wires are likely getting wet...

 

His car is a 2000, so he doesn't have an Optispark.

And while it is possible that the wires are getting wet, I wouldn't think that too likely with them being so short and right over the valve covers.

I'd be more likely to think that some moisture is getting to and disturbing the mass air flow sensor.

 

One way to find out for sure though isn't there? Next time it rains open the hood and see here the sparks are flyin' from. I had a chvey one time that missed bad in the rain and you could see the sparks jumping from the plug wires. Damp air will definitely cause spark jump. The wires don't necessarily need to be wet either.

 

The MAF is a Z06 that I bought last year, would this make any difference? As for sparks flying in the rain, haha it only happens when the car is moving, thus at a standstill there is no engine problems and no way to see if the motor is sparking.

 

The Z06 MAF might be the culprit.

If you know someone with Autotap, log the car and see if you can tell which cylinders are misfiring, if any. That might help narrow your search.

 

i have the SAME EXACT problem. She runs like a champ until it rains.. I changed my plugs and wires. Waited for rain and it STILL did it. I got it checked at AAMCO and it was cylinder #2. just about to get it fixed and i'll let you know what it was.

-Anthony

 

FWIW, my wife's old Pontiac Montana had some wires under the carpet corrode, and that caused a bunch of weird electrical glitches. It was in a big fat piece of harness with at least 40-50 wires bundled together. Where they spliced 3 or more wires together - especially grounds - was where it corroded. I had to cut the harness open and start giving a light tug on wires, a few of them pulled right out of the splice with no effort.

I stripped back and redid the splices, and that fixed some of the problems but not all of them, so undoubtedly there were more wires affected that I could not find. Her van did stuff like automatically and repeatedly lock the doors when it rained (it was fun trying to get out of the van in the rain ).

My point here is that this may be a very difficult issue to find. Hopefully it's an easy fix and they find something quickly.