98 Mystique occasional trouble starting

I have a 1998 Mercury Mystique which will periodically not start. It cranks fine but will not start. If I wait a few hours the car will start fine and I will not have any other problems for a few weeks or months. Then it will, once again, not start. Two shops have been unable to find any problem. Any ideas?

When you can’t get it to start, try this:

Turn the ignition to Off, wait a couple of seconds, turn the ignition to On (not Start, just On) and listen very carefully. You should be able to hear the fuel pump whine for a couple of seconds. If it doesn’t, I’m willing to bet you either have a bad fuel pump relay, or failing pump.

Is there any connection with moisture? Does it do it more on humid mornings or after a rain?

The last time the car wouldn’t start was during the morning after a rain. Everything was still pretty damp.

The spark plug wires, ignition coil, and other wires could be getting a damp coating from the dew or high humidity. When the engine is just barely warm, use a silicone spray on the spark plug wires and ignition coil. The silicone spray can prevent the moisture from getting into the little cracks in the coverings.