Posted this on cumminsforum and didn't get any ideas.. help dtr! 03 with 220k miles. All stock. This thing runs perfect, smooth, no smoke etc. But it cranks several times after shut off, and occasionally won't start at all. Its not leaking fuel externally anywhere, so what's bleeding off the rail pressure?

Truck runs perfect once started, never smokes white, even on startup.. I'm thinking pressure relief valve personally. Where would you guys start?

 

sounds like fuel pump to me. I had similar experience with a gasser a long time ago. Would start, idle, even get me to the first stop light and then cut out and die.

Do the key front back front back front and see if a code jumps out.

 

You need to look at 2 things to help diagnose. What is LP pressure and how much RP do you have? Then we can talk about what is wrong. Otherwise you are just guessing.

 

I have no way to measure rail pressure. Lp pressure was 15 at idle.
No codes in truck, and.like I said the truck runs perfect, when it finally starts

 

Sounds like it has a bad injector. That is the most common issue. Check all of the cross over tubes in the head for proper torque. This can be an issue also, but with that many miles if the injectors have never been done, I am leaning to an injector issue.

 

Wouldn't it smoke white on startup? It cranks and cranks and then starts perfectly. But never misses or shutters. It won't even hit now.. last time it had no start, I changed the fuel filter and it started almost immediately.. its acting like there is no fuel.

 

Tearing it down and torqing the tubes, if that doesn't work I'm putting a pressure relief blockoff on it. Figure $55 for peace of mind. Then I'll move to injectors.
Btw it starts and runs perfect with a snort of ether.. lol

 

Noop, sounds like you have an injector with a high return flow rate causing a low RP and the no start.

 

Don't leave the rail blockoff on the truck. You will have rail spikes that will definately ruin your injectors.

 

Wow I didn't think on a totally stock truck they'd spike high enough!
I broke the banjo bolt loose on top of the valve and fuel leaked out.. I figured it should be dry after shut off???

 

Oh yes, Be hard on the throttle and have to get out of it quick, that is when it will spike and the relief valve kicks in. There is a sticky post in the 3rd Gen performance section.

 

You have a high side pressure leak somewhere. Typically 3 things, CP3, Injectors/tubes, or Rail Pressure Relief Valve. Like was already said, more than likely its the injectors. There is proper way of checking return fuel, but you need to up the pressure in the system with a computer. Then check return flow from each fuel circuit.

 

I had the same issue with my '03. After way too long giving it a "snort of ether .." I purchased an injector line cap off tool (est $50) which you can get from Geno's or Hoelsi Diesel. Basically if one of your injectors is leaking you can locate it by capping off each injector port on the rail one at a time. The engine will run on 5 cylinders but will not start if the ECM doesn't see the low limit on the high presuure rail. With even one injector leaking the rail pressure can drop below the required limit and the ECM simply won't tell the electronic injectors to open. Once you cp off the leaky injector the engine will most likely start. I would start with the easy ones to reach and do the more difficult lines last. I keep the tool in my truck so I can cap off any future broken injector lines and still drive to help.

http://hoeslidiesel.com/store/page13.html

This is the tool from HoelsiDiesel.com $57

Here is a link to GenosGarage.com where they have one for $20:
http://www.genosgarage.com/FUEL-RAIL...nfo/LT-TESTCA/