Please Help with 96 Jetta starting Prblm...

I have 96 jetta and I have a starting problem.
If its parked for a long hours or overnight in a hard rainging it will not start.
Or in a wet and cold (around 30F) weather.
I have done a full tune up but it didn't solve the problem.
Please help. Thanks

Any idea...?

The ignition coils are know to short out when wet. Try spraying water & see if it starts popping/acring.

The ignition coils are know to short out when wet. Try spraying water & see if it starts popping/acring.
Thanks for your replay. It hv't rained since your replay so I couldn't test it. I forgot to mention that I'v changed the gas from reg to plus and that helped like 20% of solving the problem because it was just with a some raining I can't start it. do you have any idea? thanks again.

Thanks for your replay. It hv't rained since your replay so I couldn't test it. I forgot to mention that I'v changed the gas from reg to plus and that helped like 20% of solving the problem because it was just with a some raining I can't start it. do you have any idea? thanks again.

I'm a little confused with your post. What does it hasn't rain have to do with not being able to test the coil? You should be able to spray a fine mist of water on the coil and see what happens. You don't need the rain to do this. Maybe I'm missing something here.