supercharged94Z28

Hi guys. So just like the title says, this is what happens. It's been doing this for years and it only started bothering me because I use it as a daily driver now and sometimes it happens to be raining. The car runs perfectly fine when dry but as soon as the roads get wet, it jerks badly, and almost seems like it loses power, but never stalls out, never threw any ses lights and it idles fine, starts up fine and if not touching the accelerator when raining, rides fine. As soon as I drive about 3 minutes on a dry road, all is fine. I also taped up the 02 sensor wires, which have also been replaced about 15k miles ago. They're ac delcos. The car has 95K miles on it. Engine was rebuilt at 50K miles.

I just replaced the wires 3 months ago because of a misfire and that resolved the misfire. I replaced the fuel filter a few months ago and the opti spark has been replaced, but probably like 40k miles ago. Plugs have been replaced about 30k miles ago and are rated for 100k. I believe they're the autolites.

Thinking the opti spark may be cracked or maybe the air filter is getting water inside of it? Without a code, I just hate to start replacing stuff that doesn't need to be replaced. Any suggestions or troubleshooting tips would be appreciated.

94Z28LS1toLT1

Do you remember when the opti was changed? A cracked opti can cause a lot of issues,there's a sticky note topic about checking the opti out,I'd look into that

Injuneer

The "sticky" tests to see if the optical cam position signal is reaching the PCM. Moisture is more likely to cause high voltage cross-firing and carbon tracking in the cap and wire towers. The "sticky" doesn't test for that, and there is no diagnostic/code/SES light for that in OBD-1.

Does sound like moisture causing ignition arcing. Check the plug and coil wire terminals for corrosion. Check the Opti harness connector for corrosion... often sort of blue-green. Also check the coil for damage.

Have you opened the hood in the dark, and misted the engine lightly with water to look for arcing on the ignition components?

supercharged94Z28

Thanks for the quick responses guys. I haven't misted the car at night yet, but I'm gonna have to do that tonight. Sounds like from what I'm reading and what you guys said, that it probably has something to do with the opti. If I find out what it is, I'll let ya know. This site has helped me greatly in the past.

supercharged94Z28

Ok, so I checked for arcing under the hood last night and I only saw slight flashes of light that I really wouldn't call arcing at just about every spark plug, but it was doing it while dry. Does this sound normal? I didn't notice anything arcing while sprayed although I didn't have access to spray from underneath the car.

Injuneer

Sounds like a high voltage corona glow. Does not cause problems.

Did you mist the coil and Opti area?

supercharged94Z28

Finally got to misting around the coil and coil wire. I did see a small arc going to the supercharger intake. I thought I had changed it, but appears I missed that one. Too many beers that day.lol. I'm gonna change it out and see what happens. Just haven't been able to access the bottom to spray the opti spark. Guess I'll have to if this doesn't help. Thanks for all the suggestions Fred.

Greg