Hi, I have a 91 gti 16v, and it wont start when it is raining or wet. At all other times it runs practically perfect (I say practically because it is 20 years old), but whenever it rains, even if it just started, simply the humidity will make it not work. When it is raining the car will crank, and then when it finally catches it will just hind of give a dull thump and die, kind of like a "sigh"... This had been a problem as far back as november, but with the winter and the cold I guess it wasnt humid enough to be a problem? With the spring, all of the moisture is killing it. Right now it is sitting by my work, because it was a beautiful day and I drove it there, but then when I got off it was raining and the car wouldnt start.
The battery also died about a week ago the day after it rained. It sat all day in the rain and wouldnt start, and then the next morning the battery was dead, but as soon as I jumped it it started right up. Since then, it has rained and then stopped raining 2 times, and every time when it rains it wont start, but almost as soon as it is done it starts right up.
I have replaced the distributor cap and rotor as of 4 days ago, and the same problems are still occurring.
Any help would be greatly appreciated. Thanks!