ok here the problem i ave a 1999 suburban with a vortech 5.7..twice now it happened.
on a rainy over night next day i try to start my truck it wont start..nothin wrong with the battery or starter..sounds to me like a electrical..but yet i keep trying eventually 1 hour later it starts..what could it be...

 

There a two major ground blocks behind the dasboard. One on each side, if I recall correctly. I had similar issues with my 99 Suburban. The drivers side ground block had loose connections and was apparent it had ben arcing for awhile. Once cleaned and tightened all kinds of oddities went away. Drove me nuts for years. Very intermittent.

 

I had the same issue on my 98 Tahoe. I had to hit the gas tank with a baseball bat and then it would start. I replaced the fuel pump and check all conections and couldn't figure out why hitting the tank allowed me to start the truck. I got the tip from a Chevy tech, he couldn't answer why that worked either?

 

It works because chevy fuel pumps jump contacts on the pumps, due to bad design. The interconnects are not very weatherproof either, and so a swift bat hit often shakes enough crap back into position to work.

Take it all apart and put it all back together. My mother's truck had 3 fuel pumps in it before we learned it was the interconnects the whole time.

 

maybe distributor cap

 

Sub29 - i know this an old post, but do you remember what the solution was?

I have a similar problem.

Thank you.