Sucking air

[CaptPhil]

Do you have a lift pump? That would probably solve your issue if it is caused by loss of prime.

 

[x MadMAX DIESEL]

I'd just buy a damn lift pump, if good to have even if it doesn't fix the issue. Have someone check the vacuum on the fuel test port. Maybe you have a collapsed fuel line

 

[LB7 Lover 1994]

Well I figured I would let you all know whats going on with this and what we finally decided to do.

Early this week the mechanic called and admitted he was having a very hard time finding this leak. Luckily this has all been free labor since the injector job last month. After talking to instructors at school and several other well known mechanics in my area we have decided to throw a lift pump on it as well as a sump kit and be done with it.

Probably should have done this a month ago but I hate giving up. Hopefully she'll be back at home by the end of next week.:thumb:

 

[Kappa9012]

lift pumps should not be needed on stock trucks... besides, if it's a draw issue in the tank, most lift pumps say to NOT prime with them.

When it dies does it just shut off immediately or stumble until it dies? any smoke when it dies? Are you certain it's a fuel starvation issue?

 

[LB7 Lover 1994]

The mechanic is certain that it loosing prime and that is what is causing the truck to die. No it doesn't just immediately die it does kinda stumble then dies. But the stumble doesn't last long once it starts it lasts maybe five seconds then dies.

 

[jlawles2]

you might want to check the lines between the tank and the frame. Those are known to have internal issues.

I would also have the tank dropped and check the pickup.

 

[LB7 Lover 1994]

you might want to check the lines between the tank and the frame. Those are known to have internal issues.

I would also have the tank dropped and check the pickup.

I for sure will ask for the tank to be dropped and checked before we throw a light a lift pump on it. What sort of internal issues do they have he checked them and said he didn't find a leak so what is left to be wrong with them?

 

[chevyburnout1]

Did you or your mechanic install a clear fuel line after the fuel filter housing? That right there will prove if there is air being sucked into the system. I have a 5ft hose I splice in and run up to the windshield, then go out and drive it and watch for air bubbles.

 

[CaptPhil]

I for sure will ask for the tank to be dropped and checked before we throw a light a lift pump on it. What sort of internal issues do they have he checked them and said he didn't find a leak so what is left to be wrong with them?

The soft lines are known to collapse internally, suck flat, and starve the engine of fuel. Which is still what I think is happening with your truck.

 

[x MadMAX DIESEL]

The soft lines are known to collapse internally, suck flat, and starve the engine of fuel. Which is still what I think is happening with your truck.

Same thing I thought as well. If that's what it is, I wouldn't spend the money on replacing those lines. I'd keep the old ones and put that money to a lift pump. That will keep them from imploding and also keep your fuel system extra happy. 2 birds with one stone

 

[LB7 Lover 1994]

I am starting to agree with the collapsing fuel line theory, but if it were this would it do it all the time every time because sometimes it runs.

And if this is the case what is causing the hissing nose whenever the bleeder screw is cracked

 

[CaptPhil]

IMO, the hissing noise is air getting sucked back into the lines, since they are under a vacuum state when the lines collapse. There is no real way for the system to be under air pressure without a lift pump. none that I could think of anyway.

That is the real question though, is air going in or is air coming out? You shoudl get a vacuum/pressure gauge with an adaptor for the bleeder screw threads and test it. If it happens and the truck shuts off, will give you a pretty clear indication of whether it is a vacuum issue or not.