LBZ runs for 30 seconds then dies........

[LBZ]

My buddy has a stock '07 LBZ and since he started parking in his new garage, it's turned into a princess and is now giving him grief.

It starts and fires right up runs for 30 seconds then dies. Then you have to crank it for a bit before it fires again then it runs fine. I'm ASSuming that fuel is bleeding back to the tank from the fuel filter. So I have narrowed it down to the bleeder screw or a loose fuel filter letting air in so it is syphoning back to the tank. Does it sound like I'm on the right track?

Also are there any check valves in the system, like in the filter head or the fuel pick-up, to prevent this?

I haven't been able to put my hands on the truck as I'm gone working and so is he but I would like to have a game plan for when I get home. If we can't find it, I'm pretty sure it's getting a lift pump!

 

[tinman22]

sounds like your on the right track to me. mine used to do this on occation if it sat for more than 2 days. found a tiny leak by my lift pump at a fitting. perhaps the filter is not as tight as it should be. had that problem once also. or the wif sensor is loose?

just shooting some ideas

 

[LBZ]

I thought WIF as well but it would likely leak fuel too. It will be checked though.....
I think it's due for a filter anyhow.

 

[straightpiperoar]

I had a cracked filter housing did the same thing....very small crack hard to even see until I got it out of the truck..Hope this helps.

 

[LBZ]

Something to watch for as well. Thanks!

 

[carter_44]

Could be: fuel pressure regulator, fuel line issues, fuel filter housing leak, fuel filter bleeder leak, dirty fuel filter etc.

 

[LBZ]

How could the fuel pressure regulator be the problem? It starts fine, runs for 30 seconds, has to crank for a bit and then starts again and is fine. The problem only returns after it sits for several hours and cools off. If it was the FPR then it would be consistantly hard to start all the time no? Or am I missing/over-looking something..........

 

[wodan]

Small leak in the fuel supply line, trust me. Most likely located @ the fuel filter.

 

[LBZ]

Water in fuel sensor was cracked. Replaced it and now the truck starts fine every time.

 

[MACKIN]

There is a check valve (ball) in the filter housing.

 

[JoshH]

There is a check valve (ball) in the filter housing.

It is only closed when the fuel filter is off though. If you look in the center of the stock fuel filter, there is a little nipple that pushes on the ball. It is there to keep all the fuel from running out of the fuel line between the filter head and CP3 when the filter is changed.

 

[DMAX2007]

Ok needing advice I have 2007 LBZ and when I get the fuel system bled of air, the truck will start and run fine but then over a minute or two it will just die then I have air back at the fuel filter base. What do I need to do or what advice do any of you have to help me because it has me stumped.

 

[minerigger]

How full is the tank? How many miles on the truck? 1/4 tank issues were a lly thing but wouldn't rule it out. Filter head may need a rebuild as it may be pulling air around the seals

 

[DMAX2007]

The tank is full 214,xxx and just happened yesterday and is it normal for the plunger on top of the filter base to be sucked all the way down after it runs then dies.

 

[minerigger]

Sounds like it clasping lines somewhere if it's pulling the primer button down. Check the soft fuel lines on the frame rail between tank and engine. Sounds like possibly those are the issue.

 

[DMAX2007]

Ok thanks I'll have to check that thanks for the help I was getting lost and didn't know what to check

 

[DMAX2007]

Ok thanks I'll try that and see if that helps I was getting lost and didn't know what to do

 

[DMAX2007]

I just wanted to say thinks to everyone that gave me advice on fixing my LBZ rebuilt the filter housing and works great just wanted to thank you guys for the advice.

 

[minerigger]

Good deal always nice when it's something simple