I have a 1987 Turbo II, with Turbonety T4 Turbo and 10 pound of boost and some modifications, Run amazing good, It is a really street beast, But I have a problem when rains or I wash the car in carwash or wash the motor, I search for the cause but not find nothing wrong. When it rains or I wash engine start to fail, overflow, and goes of and it does not start until it is dried.
I change the two coil, spark plug cables, injector cables, insulate some electrical plugs. Change the TPS for a brand new one. I sealed the electrical sistem in the intake.
I check the ECU, but is dry and does not exist any evidence of humidity in her. I don't know what another thing to verify, Any advice will be well received and helpful.. Apparently my car only for sunny days

 

Perhaps you're directly spraying electronic components.