don't get your panties in a wad
your truck is still drivable (as long as the laptop is with me), I will pull those annoying engine covers off this weekend and inspect the FPR

 

I had this problem almost exactly at ~90K miles and it wound up being a fuel pump on its way out. The problem was only on startup and it was seemingly random. New pump cured all ills.

 

do i smell Walbro 255LPH?

 

do I hear an echo in here? LOL.

 

If it's the pump, that's a strange response from the pump, especially when it works fine once truly commanded on. The TWO pumps I had fail on my Yukon failed with no warning (go out to go to work, and no start). Even after 24 hours, no go. Guess that's a symptom to remember. Strange, but could very well be.

Matt... bring a fuel pump with ya! Don't ever run that truck with 2 gallons of gas in it again!

 

same strange problem with my brothers 01 3/4 ton 6.0. Tried all sorts of things till i took it to a shop and they scanned it. There was a sensor on the top of the intake manifold that also has a vacume line attatched. Don't remember what it does, but we replaced it and it worked fine.

His truck would just have a hard time started at ramdom times like when you filled it up with gas. Then it started doing it all the time and then it started to run like crap before we finally fixed it. We thought it was fuel system related too until we replaced that sensor. Hope this helps.

 

Screw it... pull the bed off, and change the sensor first. Drive around without the bed for a couple weeks, and see what happens.

 

Bet it will definatly hit the 12's with no bed on it.

 

 

ok, update time. We replaced the pump with a Walbro. After that was done it all worked fine, then it did it again, and fixed itself again. Well Matt came home and drove the truck for a week, never had an issue. After he left I parked his truck back in the garage again. Well Saturday rolled around and I figured, what the hell, the truck's been sitting for a few days. I was heading to a friend's house not far away so I jumped in the white beast. It started fine, stopped to grab some beer and proceeded to my friend's. well not long after arriving I had to go move the truck so that someone could get out... NO START! So I listen, no fuel pump prime. I reached over the tank and started jiggling the plugs on the pump. I noticed that, although it was 50* out, the wire connectors were kinda warm, not burning hot, but surely warmer than they should be. Tried the key again and it started fine. So now I'm thinking that:
wouldn't that explain the heat? I don't know. I guess I'll wait until the next failure and see if I can tell anymore. This is getting to be a PITA to diagnose b/c it works sometimes but not others.

If anyone would like to help me prove or disprove my theory let me know. At this point there is a brand new Walbro 255 lph pump in (Thanks DLH2006 and TouchofEvil04 for the help) and I'm 99.9999% sure that the pump is fine. I'm thinking it's the connectors on top, which I have a spare set of (thanks litredevil).