Runs rough when it rains, already changed spark plug wires

Have you changed your spark plug wires and distributor cap? You might have a spark jumping from a bad wire or distributor cap. Under acceleration, the amount of air/fuel in the cylinder increases and this may make it harder for a spark to jump across the plug gap. It may be finding a different path, and that is what's causing your engine to run rough. Spray water over your spark plug wires in a dark place and listen to see if your engine runs rough. Look for where the spark is jumping from a wire or distributor cap.

moisture in harness connections
spray with a silicon spray after you used compressed air to dry out everything

spark plug wires need to be replace

replace the spark plug wires

possibly bad spark plug wires, when the plug wires are old they crack from weathering so moisture can act as a conductor between each of the wires and cause it to run poorly. check the basics, fuel filter, plugs ect.

Yes they can go bad/ crack ect. But bad/old plugs cause undue stress on wires and coils, so make sure the spark plugs are the correct AC DELCO Platinum spark plugs, and just replace the spark plug wires one at a time. Take a spray bottle (windex works good) and wet the spark plug wires ans see if you can find where they may be arcing.

LEAKING BAD SPARK WIRES OR YOUR COIL PACK GETTING DAMP.IF YOU HAVE 3.0L ENGINE. COIL PACK ON BACK OF ENGINE.IF YOUR LOWER COWL SEAL IS MISSING WATER CAN RUN DOWN THE COWL WHERE SEAL SUPPOSE TO BE CAUSING WATER TO RUN BACK OF ENGINE DAMPING YOUR COIL AND WIRES.BAD PLUG WIRES WILL CAUSE PROBLEM WHEN IT RAINS.

check the spark plug wires, put water in a spray bottle and spray along the wires,especially by the coil,if the car starts to run bad or you see sparks, the wires are no good, hope this helps, Ray

replace distribudor cap

It sounds as thou you have moisture in your distributor.Pull the distributor cap off and let the car sit and dry out for a couple of days and see if that fixes the problem.