Hard Start when warm.

1989 4X4 22RE Pickup. The truck starts normally the first time after sitting awhile. When the engine has run for some time, and you turn it off it's hard to start without depressing the gas peddle. What could be the problem?

Thanks

I have never heard of anything like this before. You should check you spark plugs and your filters. I cant really think of anything else except maybe overheating but you shouldnt have to have your foot on the gas to start your truck.