2001 VW Jetta will not start until the following day!

I tried to start my 2001 Jetta. I thought it was going to start but then it didn’t start up. The engine would turn over, but it would not start up. This happened at night. The following morning, right before i called the tow truck, I tried to start the car, and it started right up! I took my VW to my mechanic and told him about the problem. They hooked it up to the computer, but no error code was detected. I drove the car for two weeks and again the same thing happened. This time, the following morning the car didn’t start. I had it towed to my mechanic and then they called to tell me the car was starting right up and the computer detected no error codes. Any Ideas what is wrong with my car???

Diesel engine or gasoline?

gasoline engine. Thanks, admatt

There are a million and one guesses.The trick is to be able to replicate the problem. Simple things like a heavy dew in the morning playing havoc on the ignition system is a possibility, but until it is analyzed in failure mode, we have to guess.