I have a 1999 Chevy 3/4 ton truck. Ive been having trouble starting it after letting it set overnight. It takes about 2-3 minutes before i get it to start, but then it starts fine all day long.


It's even more difficult to start on the morning after it rains. I have to crank it for about 5 minutes, then the engine backfires and then it fires right up.

Someone said it could be a timing chain, but it starts fine throughout the day. I only have trouble starting it after it sits overnight.

 

Maybe a bad check valve so fuel needs more time to get back to motor after sitting. Next time it has not run for a while, try turning key on & off to let fuel pump run several times before trying to turn it over.

 

You can add a check valve into the fuel line if you don't want to go through the bother of replacing the fuel pump.