I have a 2007 2500hd with the lbz engine and starting running biodiesel at a 50/50 mix with regular diesel and have had a problem. Not sure if the bio is causing it or not. The fuel system is hit or miss when trying to start the truck. The truck will crank but no fuel is getting to it, so I go to the primer on top the fuel filter and press a few times and walla the truck starts and runs just fine on the bio. The problem is it is hit or miss, I will go for a couple of days of no problems and the wham, the truck won't start and I play the whole priming game again. I have only been running bio for about 300 miles now. The fuel filter has been changed and still having the same problems. Can anybody out there help me out? :(

Did the problem start happening after the fuel filter was replaced? If so, it could be that the filter is not sealing completely and letting air in while sitting.

One question? are you running Biodiesel or vegie oil and calling it biodiesel ?? I am running vegie oil in my Cummings and have a bit of trouble with starting as well but I find that if I run about 1/4 diesel to a tank it starts ok for me. But your running 50/50 allready,I have a friend with a Duramax running my oil with no trouble as well it's a 07.
Vigie oil will get thick when its cool out side not cold all it takes is cool and that too can make it hard to start! try adding some Ctane Bost to you tank and see if that helps.
Wish I had more for you but that all I can think of at this time best of luck.

I was having a similar problem to that over a year ago, and come to find out, the air bleeding screw on the filter housing was cracked and letting air into the system, there for loosing prime. Something to check. I don't think it is a bio problem.

It started with the second fuel filter (17000 Miles) Don't know if it is coincedence that it was on my first tank of bio or not. The dealership replaced the fuel filter and it is still having the intermittent starting problem.

Thanks, I will check that out. I bled it the other day and it let out a hiss when I opened it. It should never do that unless something is wrong right?

Sounds like air is getting somewhere. My guess is at the bleeder screw seal or one of the fuel filter o-rings.

I had my fuel filter changed once at the dealer, and the next couple of days also had this similar problem (seperate incident from the bleeder valve). What I found was their was still air in the system causing the problem. There was air between the filter base and the injector rail. Apparently the dealer didn't know how to bleed it. To solve the problem, I would pump the system up until the plunger was hard to push, then at the front of the engine, their is a shrader valve on the fuel line going to the fuel rail, I released the pressure by pushing that down until fuel came out. I repeated this 3 or 4 more times and the problem went away. Hope this helps

Sounds like air is getting somewhere. My guess is at the bleeder screw seal or one of the fuel filter o-rings.

yes its the o-ring on the vent. Mine started leaking air. I would pump up the primer and watch for a few seconds and fuel would start oozing out. Use a -903 viton boss o-ring.

if you're getting a hissing sound when opening the bleeder, it means that you got a restriction and it starts to creat a vacuum.
I had that issue with my work truck a Cummins, the problem was this,
Cummins uses a pre-filter, it sits on the engine block before the lift pump.
"Every time the truck stalled and I opened the fuel/water drain on the filter it made that hissing or gassping for air sound"
The pre-filter got clogged from a bad mix of fuel that had alot of transfat in it.
Pre-filter sits before the main filter and no amount of changing the main filter will help you as I found out. Not shure if our D-Max has a pre-filter or not but it shure is worth looking into.
So I would start by looking into fuel restrictions some where.......... Fuel cooler etc.

Sounds like you definitely have a fuel priming issue. There were few people that had issues with their fuel filters, and the WIF housing cracking. They were bad fuel filters. There was also an issue with the aluminum housing that the fuel filter spins on to was cracked and letting air into the fuel system. I would start around the fuel filter and check the filter and the aluminum filter head and work out from there. Keep us posted on your results! Good luck!