I have a '91 Honda Civic LX that has trouble starting in wet weather. It works fine in dry weather. The rubber strip under the front part of the hood is loose - the holes that help hold it on are worn out. But it seems to me that wouldn’t necessarily cause the car not to start in wet weather. Is the loose strip the reason, or is it more likely it is something else?
If you mean the engine cranks over normally, but doesn’t fire up, the problem could be with the secondary ignition system. The secondary ignition system comprises of the distributor cap, rotor, sparkplug wires, sparkplugs, and the ignition coil.
As these components age and break down, they become sensitive to moisture. So an engine will start fine in sunny/dry weather, but fail to start when it’s raining or even foggy outside.
So if it’s been quite awhile since the secondary ignition components have been replaced, or you don’t even know when the last time the secondary ignition components were replaced, I’d start there.
Tester
Replace the spark plug wires. It should help. If you still have trouble with wet-weather starting, replace the distributor cap, etc., but in many cases new plug wires will do the trick.