Thread: Wont start warm

http://en.wikipedia.org/wiki/Vapor_lock

check fuel pump operation. But I've never seen a fuel pump fail half way. They are either working or they are not working. And if they're working, chances are you wont get vapor lock.

I'd just go over the engine with a fine tooth comb and make sure nothing is loose or leaking

Bad fuel MIGHT cause it, but I classify bad fuel as sitting longer than a year. Winter blend won't vapor lock and more than summer blend will. And higher octane won't do a thing except cost you more money. Your truck requires 87, give it 87. Higher octanes are meant for higher-compression vehicles which need advanced timing.

Do you have an CELs? When you start the truck- do you go from key in straight to start or do you stop at the "ON" position for 2-3 seconds to let the fuel pump pressurize the line? I'd try that next if you don't already. If nothing, I'd look into checking the fuel pressure at the fuel rail.