Fuel air leak in tank

[kkriese]

After 3 months of trouble-shooting, i believe I have diagnosed my air-lock problem. The problem is hard to find because my truck starts well for 10 to 20 starts, then won't. I crack the injectors, prime, etc and it fires up and then runs fine again. First I installed a new filter, checked all hoses, made sure the lines weren't frozen. No diesel leaks and all seemed fine. Then I installed a new filter housing/primer pump (a single unit in 2LTE). Then I installed clear plastic hose on the outlet of the primer housing and on the fuel return line after it exits the fuel pump (see photo). When running, no bubbles were evident, but when I would run for a longer period of time, a single bubble would appear in the line just after the primer housing. My theory was that a small air leak was in the fuel supply, and air bubbles would build up in the primer housing then "burp" down the line and create an air lock.

I then installed all new fuel line to the tank (just bypassed the lines with rubber hose) and a clear hose right outside the tank. I can now see (sometimes) very tiny bubbles coming from the tank; the bubbles are about the size of a pin-head, and one passes by every 3 to 10 seconds; so not much air, but maybe enough for the "burp build up" theory.

So, my next step is to remove the tank and repair/replace the fuel pick-up.

Has anyone done this, and any other ideas before I tackle this (weather permitting) this weekend?

thanks,

kevin

 

[Radd Cruisers]

Been down this road many times...

Small (tiny) amounts of air won't affect a pump that flows a lot of fuel through the return line like a 2LTE.

When you get the 1 in 20 won't start scenario, are you actually getting a lot air out of the filter?

Perhaps you should look at a sticky or intermittent fuel cut solenoid.


~John

 

[roscoFJ73]

So, my next step is to remove the tank and repair/replace the fuel pick-up.

Has anyone done this, and any other ideas before I tackle this (weather permitting) this weekend?

thanks,

kevin

There was another guy last week(was it you?) He rigged up a temporary fuel supply and set it close to the engine bay.
When he was confident there was no bubbles,he connected it to the fuel lines at the tank and again he saw no bubbles,leading to the conclusion it was the fuel pick up which had a pin hole in it.

I dont think you need to remove the tank.Under the carpet in the rear floor there should be an inspection plate that will give access to the fuel pick up.

But like John said ,check the fuel cut solenoid. People have been stuck in the wilderness for days because of loose fittings on the solenoid

These threads should really be in the diesel forum