ok i have a 99 gmc jimmy that a few mouths ago had starting problem well now i have another problem with it starting. truck will start on first try in morning but after driveing a few miles and shuting it off it does not want to start have turn off and on two or three time the it will start

When you turn the key for the 1st warm start, do you here any clicking noises from the engine?

And when you say it won't start, does it do nothing at all, click as asked in the previous post, or just crank for a long period without firing?

Sounds like maybe something is heat sensitive!