Hard Starting after truck is driven

[RTICWOLF]

Hello everyone!

I have a 99' Ext Cab 4.8L 4x4. When I leave the truck over night or for several hours (like during the work day), everything is fine (although the truck does not start with the normal "tap" of the key like it used to). But if I drive the truck and then let it sit for a few minutes (about 20 or more), and even after 4 hours it is hard to start. It turns over very easy (and sounds fast...like its not having to work to hard to crank) but I have to give it a little gas to get it started. It then sputters until I rev the engine a time or two. No codes and no lights present.
I have just changed the oil (Max Life 10/30), new plugs (Bosch +4's), new fuel filter, new PCV valve, and cleaned the K&N filter (CAI) and throttle body with no change. Temperature does not make a difference as it has done this on warm days (80+ and 90+ degrees) as well as cool days (40's and 50's). Any ideas of what is going on? It has just turned 90k miles. All fluids are new except the anti-freeze, but it looks good and tested to -30 below.

Please help, I fear its going to leave me stranded someplace soon as it is getting worse.
Thanks!

[sdowning1967]

I also have a 99 extended cab 4x4 but with the 5.3L. I would check the fuel pressuer regulator. Pull the vacum line off after you have shut the motor off and let it set for a couple of min. If gas runs out the regulator is bad and needs replaced. Mine did the same thing.

[Arsenik111]

do you lose performance from this during driving

[internic]

i would def agree check the regulator, if that is not the culprit the IAC valve could be sticky or bad?