I have a 96 Lexus Ls400 that runs very badly when it’s wet out have replaced both plugs and wires And I have no clue what is wring with it
In the dark, using a spray bottle, mist your engine with water while running and look for arching.
I’ve tried that but no visible arcing also seems to happen when the car refuses warm up
If the engine is misfiring when it is damp you might consider replacing the distributor caps.
There are two distributors, one on each cam gear. I remove these when replacing the timing belt on these cars and they are usually very dirty inside.
If the temperature gauge does not reach the normal temperature position after 5 miles the thermostat might be leaking.
Ty it doesn’t happen all the time it only really refuses to heat up when it’s damp outside after heating up it runs perfectly fine