engine light on

[Flyinb]

Here are my symptoms.. I hope someone can help out:

Engine light comes on
LAcks power
Happends mostly in wet conditions
Cap / rotor / ignition wires, spark plugs all just replaced.
Soimetimes engine light will be on, then after I drive for a bit, it will shut off (in wet conditions)
No backfires
starts fine
idles fine

Any ideas? I am pretty handy with engines, and can check most things out.

How do i check the engine codes? <-- nevermind. figured it out. gonna check tonight...

TRUCK:

1987 4-runner
22R-E engine
4 speed auto with ECT
Stock Everything

Thanks!!