My '89 740 Turbo, 115K miles, has trouble starting up during very rainy days. Sometimes the engine does start up but stalls while driving... other times it won't start at all. I do hear the engine turning over, but it doesn't 'catch'. What I do in these situations is I keep on cracking the engine, sometimes for 15-20 minutes, until things seem to 'dry up' and I feel the engine starting to catch. From that point, it's usually another minute until I can get the engine to run stable. Well, at least for a few minutes - sometimes it stalls again later.

The battery is brand new. Full tune-up was done about 1 1/2 years or 15,000 miles ago.

This is definitely water related - I have no stalling and no-starting trouble in dry weather.

I have read through the FAQs, but am confused how to approach this. Also, someone recommened spraying WD40 or another water-repellant spray on certain parts of the ignition system. Does anyone know if this is true, and if yes, where do I spray this?

TIA!