G20 start issue

[pathalter]

My 1993 G20 is having start issues. My mechanic checked fuel system and says all checks out, fuel pump pressure slightly low but within range. Problem sporadic, sometimes it starts right up, sometimes must pump gas while starter cranks. Starts best if I turn the key and let sit for 10 seconds and then start it (I can hear the fuel pump pushing fuel to fuel rail). I've noticed if weather is wet it's harder to start. If it's dry with low humidity it starts right up. Mechanic says he'll replace fuel pump for $400 but is not sure that is the problem. I would rather know for sure what problem is rather than throwing parts at it. Any advice would be appreciated.

[nametakennow]

Could be the pressure regulator itself, given that it's sporadic. Run that by the mechanic. That part should be cheaper as well.