Looking for some ideas. I own a 1995 Honda Civic DX with a D15 Automatic. It has trouble starting after a good day of rain or if was humid overnight, trying to start it in the morning. It will crank & crank & crank. Almost every time it EVENTUALLY will fire up. During this cranking process once I hear the click from the dash, it fires up. I have checked distributer/cap, spark plug wires/plugs, coil, air intake/filter, battery, alt, and I even replaced the Main Relay. I was thinking that maybe it could also be the starter relay. I would really appreciate any ideas at this point. It has been a frustrating 2 years with this issue.

 

here's a line up of the usual suspects:

Honda Acura Essential Electrical Repair Website. Troubleshooting Main Relay, Coil, Igniter, etc.

 

Moisture seeping into ECU or bad capacitors in ECU?

 

Next time it does this after a rain try spraying WD-40 on spark plug wires and distributor cap before starting.
Read this: SOLVED: Does 1998 Honda Civic have a starter relay? If so, - Fixya
Read this: https://honda-tech.com/forums/honda-...rains-2971346/

 

I would bet 80% chance it is failing electrolytic capacitors in the ECU. As humidity increases it changes the resistance in the component and will delay fuel pump circuit prime. this is a common failure for Honda civic and accord from 91-97.