jeep gremlins playin games

bought another jeep 95 2.5 5speed, wouldn't fire up, mechanic said he replaced crank sensor, said ground or computer was bad. i sanded all grounds, fired up ran good, passed inspection(thats another story)ran around everywhere ran great, next morning wouldn't fire, turned over then nothing continuous clicking from relay fuel or auto shutdown, replaced fuel relay, napa only had one, ran good all night, next morning same thing clicking from relay????? then i get home from work fires right up ran good...what gives ...relays? .... fuel sending unit going bad or is there a switch on neutual
signed dazed and confuzed

now it seems to fire up and then die right away, 2-3 4 times or so , buddy seems to think its still a grounding issue?? moisture with the morning, will try dieletric grease on all ground points......