GreenZLT1

I seem to have a problem where the car will not start (from a cold start) in high levels of humidity. I drove my car a couple places this summer where it got rained on over night. The next morning, the car would crank and crank. I would set a hair dryer near the optispark and it would finally fire up after awhile. Also, when my car would be sitting in the barn on a very humid day, the car would act up. The weather has been less humid here lately and I haven’t had any problems. Is it possible that a cracked cap and rotor could do this? Or am I overlooking something else? I believe the car has no spark when it is doing this due to the black/brown smoke the emits from the exhaust when it finally fires up.

Thanks,

Rob

Injuneer

Have you checked the Opti terminals and plug/coil wire ends for corrosion? Ditto on the Opti harness connector. Could be worn out plug wires.

Guest47904

I have the same problem with my 94. Never heard of this problem with vented units though. sorry got to live with it.

bw_hunter

I had this on my wife's 95 Formula..with it's vented OPTI. It turned out to be bad plug wires.....

tricky69

i have a 1994 Z28 that when i drive in the rain the car idol will get messed up untill i give it gas when i come to a stop. i thought it was the plug wires as well but replaced wires and still have the problem. so please let me know if you find anything out.

bw_hunter

The next time this happens, saturate the OPTI with WD-40. Just spray the heck out of it. If the distributor cap is 'water logged' WD-40 (or CRC 5-56) will displace the moisture and improve the idle. If this works I'd recommend replacing the OPTI or, at the very least, the cap and rotor. For your sake use only GM parts (delco or delphi are GM parts) or you risk problems later on....