Problem of starting at rainy day


#1

1989 Toyota corrolla wouldn’t start whenever it rain even little drizzle, the battery is find but wouldn’t start until the dry or sun shines on it. What is problem or cause this.
Thank you.


#2

I’m betting you have no spark, either due to ignition wires arcing to the engine when wet or due to the coil or distributor parts being invaded by moisture when it’s wet outside.

Spark is easy to test for. You can use a spare plug, grounded against the engine, or a simple inductive timing light.

If you have arcing from the wires, you’ll even be able to see it at night while trying to start the engine. If the wires are old, change them… one by one so you don’t accidentally cross them up. If you have no spark and no arcing, go backwards into the distributer. Change the rotor and distributor cap and see if that helps. If not, you may have to take it to a shop to test the coil. The shop will need to check the output of the coil on a scope and perhaps check the 12VDC signal on the coil “primary”. You can’t check this with a regular meter, because a regular meter will only give you an “average” voltage and you need to see the pulses to know the primary signal is good. A coil will not function on a constant voltage.

By the way, when was the last time you did a full tuneup on this car?


#3

+1 for @mountainbike. It’s definitely in your ignition system somewhere. In my experience…it usually turns out to be bad spark plug wires. Misting them with water on a dry day then trying to start the engine will usually give them up as faulty.