I have a 1996 f22b2. When I go to start the car after sitting for a few days, sometimes it randomly doesnt prime the fuel pump. When the key is turned to on, normally the cel goes off after a few seconds and the fuel pump audibly primes. Sometimes however, the cel doesnt turn off, and the fuel pump never primes. This causes the engine to turn over but not start. Once the cel turns off, the car starts right up. Ive heard moisture in the ecu can cause caps to go bad, but ive opened up the ecu and not a single cap looks swollen or like it lost its guts. Should I try and replace the fuel relay under the dash? Thanks

 

Your main relay is going bad.

 

https://web.archive.org/web/20211202...mainrelay.html

But before you dig into the main relay, do a quick check that it's not the ignition switch being sloppy.
Jiggle the key around when left in position II(ON) to see if anything happens. Switch is pushing 30 years old it may be crapping out.