Sucking air

[LB7 Lover 1994]

Guys I'm about to go nuts two monthsnow with this thing doing this and it is still dying after losing prime.

This is an updated list of everything that has been done:

The fuel lines running from the filter base to the FICM have been replaced.
The filter base is brand new.

They took a charge pump and connected it to the lines directly after the tank they put 160 pounds of pressure on the fuel all they found was the banjo bolt on top of the FICM was loose.

They tightened it down, kept it and drove it around for three days before calling me and saying it was done.
I went to pick it up drove it around for 45 minutes after going out for lunch we left the place pulled up to the red light and while sitting at the white line it died.
I got out cracked the bleeder screw and a small burst of air hissed out.
I tightened it down and began to pump it to get it started again and drove it straight back to my mechanics house.

I am about to pull my hair out what could be causing this?

 

[02greysixer]

You looked at the fuel pickup in the tank at all?

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[LB7 Lover 1994]

The mechanic made mention of it today whenever I stopped by but I don't remember whether or not he said he thinks its that or he thought it was that and has already checked it.

 

[04D_MAX]

Try a lift pump and delete the stock filter head.

 

[LB7 Lover 1994]

That really is just putting a bandaid on the situation though is it not. I know that would probably fix it but that a pretty expensive bandaid.

 

[MACKIN]

To see if it's the pick in the tank the tank would have to be dropped or the bed removed so did he check it? Putting a lift pump on it isn't a band aid IMO. It might also help diagnose

 

[chevyburnout1]

Just curious, when you cracked the bleeder screw are you sure the hiss noise was air coming out versus being sucked in? Stock fuel system will have no pressure in there to push air out. Unless you primed it then cracked it open.

 

[02greysixer]

My money's on a pickup or hard plastic line issue. If your truck is a short bed with the standard 26 gallon tank it can easily be dropped by one person in no time.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[DAVe3283]

My 2003 has gone through a in-tank fuel pickup already. It had a small crack in the plastic flex line, and would start sucking air below 1/2 tank. Putting a lift pump on kind of fixed it, because it would return that bit of air to the tank. Eventually, the hole got too big, and I had to replace the pickup assembly.

Also: totally worth getting the new design assembly. I got mine on Amazon for $275. Not only did it fix the air leak, but it fixed the fuel gauge being jumpy, and the new one flows a LOT more than the old one. Still not as much as a draw straw, but probably 30-50% more than the 2003 model.

Finally, you might be surprised what is in the tank when you look. When I pulled the pickup out, I found a foam bottle seal from a additive bottle had fallen in, and was sucking up onto the bottom of my pickup. No wonder it only ran well when the tank was full...

 

[04D_MAX]

Sump it with a lift pump problem solved.:thumb:

 

[Dirtymaxx03]

Did you check all the lines from the tank to the filter head. There's a lotta fuel line to possibly sucking air, gotta check all of it.

 

[LB7 Lover 1994]

Yes all the fuel lines from the tank to the filter housing were checked. The mechanic thinks that it is either an o-ring in one of the quick connects or it is the pick up in the tank.

 

[MACKIN]

To rule out the pick up (draw straw) do you have the problem with a full tank of fuel?

 

[LB7 Lover 1994]

It does it no matter what the fuel level is. Two weeks ago I stopped at a gas station and filled entirely up with fuel. As I pulled out of the gas station it died and I had to pull of the side of the ride and start it again. Once it started I took off it died literally 10 seconds after i put it into gear.

 

[CaptPhil]

Just curious, when you cracked the bleeder screw are you sure the hiss noise was air coming out versus being sucked in? Stock fuel system will have no pressure in there to push air out. Unless you primed it then cracked it open.

I like that theory more.

Collapsing fuel lines maybe? causing a vacuum in the system.

 

[Dirtymaxx03]

Have you checked the rubber o ring on the bleeder screw?

 

[LB7 Lover 1994]

I'm starting to think the same thing honestly especially after having 160 pounds of pressure on the fuel I would think that any fuel leak at that point would have been extremely noticeable.

In theory how much money would it cost to replace the lines between the tank and the engine itself?

 

[LB7 Lover 1994]

Yes I have and so has the mechanic we don't think its anything on the filter housing since it is all brand new.

 

[Chavez91]

Have you checked any of the hard Lines?

 

[LB7 Lover 1994]

The only ones that i know for a fact have been checked are the ones listed.