Any ideas what could be causing my previously reliable used Corolla to not start every time it rains?

Dear Car Talk | Mar 01, 1997
Dear Tom and Ray:
TOM: Help you? You've got the world's most perfect car, Kimberly! Do you know how much work I could miss if my car wouldn't start for four days after every rain shower? I'd never miss a daytime rerun of "Columbo" again!
RAY: You'd best ignore him if you ever want to graduate, Kimberly. Let's start with the basics. Water, or even just moisture, can interrupt the flow of electricity from the ignition coil to the spark plugs. And if the electricity doesn't get to the spark plugs, the car won't start.
TOM: And the "classic" parts that get affected by moisture when they're old are the spark-plug wires, the distributor cap and rotor. They're all relatively cheap, so I'd start by replacing all three.
RAY: My guess is that will fix it. But if it doesn't, the problem may be in the igniter assembly, which is inside the distributor. And that requires replacing the distributor itself, which costs many hundreds of dollars. So if you need another distributor, I'd look for a used one in a junkyard.
TOM: Alternatively, Kimberly, you could just transfer to Arizona State. With all the nice, dry weather down there, you probably wouldn't miss more than two or three weeks of classes a semester.
TOM: Help you? You've got the world's most perfect car, Kimberly! Do you know how much work I could miss if my car wouldn't start for four days after every rain shower? I'd never miss a daytime rerun of "Columbo" again!
RAY: You'd best ignore him if you ever want to graduate, Kimberly. Let's start with the basics. Water, or even just moisture, can interrupt the flow of electricity from the ignition coil to the spark plugs. And if the electricity doesn't get to the spark plugs, the car won't start.
TOM: And the "classic" parts that get affected by moisture when they're old are the spark-plug wires, the distributor cap and rotor. They're all relatively cheap, so I'd start by replacing all three.
RAY: My guess is that will fix it. But if it doesn't, the problem may be in the igniter assembly, which is inside the distributor. And that requires replacing the distributor itself, which costs many hundreds of dollars. So if you need another distributor, I'd look for a used one in a junkyard.
TOM: Alternatively, Kimberly, you could just transfer to Arizona State. With all the nice, dry weather down there, you probably wouldn't miss more than two or three weeks of classes a semester.
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