93 civic, weird problem to start, MAIN relay okay.. help please
 

Civic 1993 DX, 1.5L
About 3 months ago my civic start giving hard time on starting. right after igntion key is turn ON the CEL would stay on for like 1 - 2 minutes, after turns OFF the car start perfectly, with the CEL ON the car would not start, the engine turns well, there is spark on the plugs.
I changed 3 times the main relay and still do the same thing, only that past few days is taking about 5 - 7 minutes to the CEL goes off (and I can hear the fuel pump working for a few seconds) them car start perfectly and works all day long with no problem. I noticed that when it rains a lot the problem is more intense.
I am 99% sure that it is not a main fuse problem. What you guys think that could be? (Ignition switch? computer? MAP Sensor?)

Thank you for any help suggestions

Note: After car runs there is no CEL light so there is no code registered to lookup