03 04 6.0L Turbo Cranks - No Start

[robdog73]

I'm a soldier in Iraq. I'm a mechanic in my unit.Mostly work on 6.2,6.5,and 6.5 Turbo HMMWV.(GM.)We have 4 up armored F550 with the 6.0L Turbo. The problem we are having with all 4 trucks is that in the mornings they just crank. After cranking for a while with the acc. peddel pressed to the floor they will slowly start to run. Almost like its starving for fuel. After running for 5-10 mins. They will start for the rest of the day. Neither water nor air appears to be in fuel sys. and wait light working. this morning pulled glow plugs out and they were covered in oil. Any tips? /forums/images/%%GRAEMLIN_URL%%/banghead.gif

[Keith Browning]

Rob,

 

It's an honor to have you and welcome to FDDTS! Before anyone jumps on this, What kind of diagnostic equipment to you have and can you monitor engine/PCM parameters with a scan tool?

 

I also noticed a post on the FTE web site... are you using jet fuel in these trucks? (JP8)???

 

The oil on the glow plugs could be because oil sits around them on the head and when you remove them the oil tends to coat them. This is not always the case though and if they smell like fuel you may have a big problem. It could be a fuel or injector related concern... due to the fuel or you may be developing a compression problem. The big factor and unknown is what exactly is jet fuel, how does it differ from diesel and what does it do to seals, how does it burn etc... most importantly, get back to us on the first questions above in bold.

[robdog73]

Keith,

 

Sorry about the post, didn't know what I was doing. New to this forum stuff.

 

We are using JP8 fuel. Thats all we have available. We have no test equipment for these trucks. What tools we have are your basic hand tools and spec. tools for GM's 6.2L and 6.5L. What do you mean by oil sitting around the glow plugs? Eng. has no signs of ext.leaks. When we pulled the plugs the oil looked fairly clean(clear) and was almost dripping of the plug. we only pulled the plugs from the truck that is hardest to start,but the other 3 are acting the same. I have read that the 03 and 04 6.0L had a problem with valve stems cracking and leaking oil into the cyls.(I guessing they may have ment valve guides?)How poss. is that? Also did not smell any fuel on the plugs.

[robdog73]

Also more info. The eng. oil been changed resently and the avg. milage on these trucks are at about 4,800 mi. But our trouble child only has 2'200 mi. on it. Once we do get the trucks started they will run all day untill they set overnight.

[Keith Browning]

Nobody, including myself has stated the obvious. /forums/images/%%GRAEMLIN_URL%%/rofl.gif If you don't have any scan tools that will allow you to connect to these trucks to perform self tests and monitor parameters then may I respectfully recommend that the U.S. military get some appropriate diagnostic equipment? Working on modern diesel engines, computer diagnostics are a must!

[robdog73]

Kieth,

 

Thanks for your time and input. We'll see what we can do about getting some fuel additive.

 

We have another guy looking at other forums and I Laughed my a-- off at a reply he got. " I love Bush, but for cring out loud could he get you some diesel!" I sure wish we could.

[HGM]

Robdog,

First off thank you and all your buddies for what youre doing for us over there.

 

I'm with Kieth, it has to be the fuel.. Try the additive he recomended and change the filters. The 6.0L has 2 fuel filters that must be changed. We have had some serious issues with fuel quality and low pressure destroying the injectors. Keep us posted and we'll help the best we can.

 

Keep up the good work, we look forward to you guys coming home safe.

[Keith Browning]

Hey, so what was the outcome of this? /forums/images/%%GRAEMLIN_URL%%/shrug.gif We want to know what jet fuel does to a 6.0L!

[Torqued_Up]

Hey robdog, what was the fix?

 

BUMP!

[robdog73]

Well guys sorry I haven't replied in a while. I am home now. I want to thank you for your help and allowing me on your site. We never figured out the problem. Think it was the fuel also. Before I left they were going to replace all 8 injectors and the fuel pump. I gave my replacements my e-mail address to let me know how that all worked out. As soon as I hear from them, I will let y'all know. Once again THANKS! SGT. Robert L. Davis