VW Jetta

If it cranks good but won't start, have a helper crank it while you check for spark at the plugs. If you have spark everywhere, use a gage and check fuel pressure. Check for applicable trouble codes.

You have to test when the problem is ongoing.

The question is why does it Quit when it RAINS?What does the rain have to do with the fuel pressure?

I'd have to test when the problem is ongoing. My guess, something is getting wet.

You didn't mention anything about fuel pressure in your first post. Check voltage and ground at the fuel pump relay, when the problem is ongoing. Terminal 30 shows to be hot all the time. Terminal 86 goes hot with the key on. Terminal 85 is ground for the relay, controlled by the computer. When relay is energized, terminal 87 should carry voltage to fuel pump.

Fuel pump? Fuel Relay? Is any of this stuff exposed to the RAIN?I dont think so.Why does the car die in the RAIN? The original POSTER of the question is not going to get out right where the car died ,IN THE RAIN & check the fuel pressure or the relay.It is not a regular problem ,only happens when wet.What is exposed to the RAIN or gets splashed that causes the car to die?

All I can do is help you with testing. Maybe somebody else can help you better? Have a good day.

It is not my car,but i have had similar problems.Thanks anyway.The fuel pressure relay is under the dash board on the car in question.Again think RAIN.