I have a 2000 Forester that is very difficult to start when it's wet outside. On dry days the car starts without any problem. I've had a similar problem with a car that had a cracked distributor cap but the forester uses a distributorless system.

 

Would replacing the ignition wires most likely solve this problem? Is there soemthing else I should look at?

 

Any help would be greatly appreciated.

You could try looking at the engine at night while this problem is happening. Have someone crank the engine and see if you can spot any arcs from the ignition to ground indicating a weak point in the insulation. You may also want to check the spark as it may not be firing like it should. If you have a spare plug you could use it instead of removing one in place already.

 

Another thing that may be going on is that the problem is being caused by a bad connection to one of the engine sensors, like the CAS, so it would be good to check them also.