Lots of Air in Fuel....

[hoop]

I am getting air in my fuel. It is either coming from my IP or getting back feed from the injectors(if that is possible).
I have checked the bypass from the injectors and it is not coming from there. I get a lot of air when I disconnect the overflow valve assembly, and it is coming from the injector head side.
Any suggestion?

"edit"
I am getting air "Pressure" in the fuel system, even without the pump on.



Hoop

 

[WillWagner]

The overflow is on the return side. It is normal to have fuel that looks airiated there. That is the fuel the pump uses for cooling. There should be very little to no fuel comming form the injectors. Air in fuel will give a hard start complaint, low power/white smoke, start and die... Does the truck run OK?

 

[hoop]

No, the truck does not run OK.
When I bleed the air out of the system, it will start and run for a couple of minutes.
Then the air is reintroduced to the system and stalls out.
When I open the bleed valve there is a lot of pressure on the system, even with the pump off.
I just use a little thumper pump.

 

[doghead]

Inspect all your fuel lines very carefully. You could have a split rubber hose in the fuel tank(in tank pump). Is your tank full or low? Does it do this with the tank full to the top?

Have you changed fuel filters lately?

 

[WillWagner]

Agreed, Pull the pump and look at the hose. If it sat it can be hard and cracked. Another thing, check the copper line that crosses over from the primary filter under the alternator, across the bottom of the front x-member. It could be squished flat and what you see as air could be just a giant restriction. If all that looks good, do the filters.

 

[maddawg308]

Your deuce is having gas.

 

[hoop]

The only time it gets air in the system is when it is running.
My intank pump does not work, I use a thumper which is located at the tank. I can leave the thumper running for hours and it will not put air in the system, but run the truck for 10 seconds and I have air in the system.

 

[airmech3839]

probably filters not seated properly... I thought it couldnt be my filters cause they werent leaking when the intank pump is running... I would get lots of air while running though... My primary was to blame!! Once it was seated right it was gold!! Filter bowl seals are sneaky cause they wont necissarily leak out fuel but when the mechanical pump on engine is sucking the fuel out of the tank it draws the air in and then you get the sputters... I would change out the filters and bowl seals or get the spin on kits and eliminate the issue!!

I have been there and done that!! But its my

 

[hoop]

OK
There is "Pressure" in the system....
If I had a filter or line leak it would cause air to be sucked into the system which would cause a "Vacuum" in the system.
If I do not use my pump I still get "Pressure" in the system.

 

[Floridianson]

The only time it gets air in the system is when it is running.
My intank pump does not work, I use a thumper which is located at the tank. I can leave the thumper running for hours and it will not put air in the system, but run the truck for 10 seconds and I have air in the system.

Intank not running could pull air from bad rubber line in tank. Could try and fill to top with fuel and see if it stops. (you need intank to get full performance)
Air can not enter after IP fuel pump as fuel would leak out anyplace after that.
The line after tank( with no intank pump) had a hole it could pick up air or the primary filter not seated right. Good luck

 

[jasonjc]

He keeps saying that he is get air pressure in the fuel with the truck running. I would say look for a vent line crossed with an air line.

 

[hoop]

Found it.....
Thanks to Airmech3839 and Floridianson...
Without the intank pump the fuel is under suction from the tank thru the primary filter....then the IP takes over and pressurizes it to the secondary and final filters on to the Hydraulic Head.
I found a leak at the primary top nut and in the line coupler just before the IP.
It was sucking the air and the IP put it to pressure.
I thought all the filters were before the IP, only the primary is.
Thanks Guys

 

[hoop]

Another update....That was 1 leak the other 1 i found yesterday.
I had disconnected my cold start intake thingy. The fitting that I used was leaking.
I finally found the leak by bleeding the air out of the system and plugging the the return line and putting 110 lbs of air on the system......I found it.