Ran out of fuel.

[ford50gt]

Hello Folks,

I ran out of fuel on my front tank, was on a steep incline at a stop light, not really out. I switched to the rear tank that was full could not get the truck to start. I pulled the fuel filter and filled it with fuel and oiled the gasket and reinstalled, truck started.

Now if it sits for 10 minutes starts hard 3 to 5 15 second cranks. Runs terrible surges when at highway speeds, will violently buck at cruise throttle at say 30 MPH I have to either let off or floor it.

This thing started flawlessly before this happened. I really don’t think it is the return lines on the injectors.

I have taken the filter off twice since then and it is half to 2/3rds full, I bleed the schrader valve and get puffs of air out, it never stops venting air.

Any ideas?

1992 7.3 IDI

 

[justinray]

It probably just needs to bleed the air out of the system.

 

[argve]

now that you have cracked loose the fuel filter is the seal leaking. You are sucking air from somewhere which is allowing the fuel to drain back to the tank. I would start with the filter housing location first as that is what you messed with, most seals are only really good for one time only.

 

[theguruat12]

Definitely a starvation issue while driving, I had this same problem while running, for me it was blockages in the supply lines

 

[icanfixall]

Its sucking in air and the only place you messed with anything is the fuel filter. Might try some grease on the filter gasket seal. If that repairs the problem you know what needs to be done. As posted those gaskets are usually best used only once. How many miles are on the filter now. Might need a change..

 

[ford50gt]

About 2500 miles are on the filter.

I guess Ill invest another 30 in a filter and try that it's the cheapest thing.

May try clear line in a couple of places to look for air.

Can the tank selector valve introduce air into the incoming fuel?

It is a lot of air, I will replace the fuel filter, bleed the schrader until I get zero air then crack all the injector lines and see how it goes.

If I still have trouble I will install a temp under hood tank and run on that and see if I still get the same trouble, that will isolate the valve.

Under normal operation does the fuel flow back to the tank or to the filter housing? I have read somewhere that it recycles it back to the filtered side of the housing to avoid refiltering it. Cant remember where I read that though, if that is the case why have a line goe back to the tank?

This is my first Navistar, I have worked on quite a few 2 stroke Jimmies and those engines with the expensive yellow paint.

 

[icanfixall]

Once the fuel goes out or or into the return lines its a one way trip back to the tanks. It never gets recycled into the filter unless its sucked from the fuel tanks. More than 80% of whats sucked out of the tanks is returned. The diesel fuel is used as a lube in the injection pump and a coolant. The returns off the injecters are also a coolant. Very little actually gets combusted in the cylinders compared to what comes out of the tanks. Please try the grease on the filter gasket before you replace a filter with 2500 miles on it. That might fix it and its a free repair if it works.

 

[ford50gt]

Will do, I will let you know.

 

[chris142]

I have ran out of fuel a few times. Mine takes about 20 seconds of cranking but so far has always started. It will run rough for a while afterwards. Sometimes it will run rough the next morning even.

 

[73IDI]

If you ran out of fuel and cranked on it afterwords you most likely have air in the lines and will have to blead every injetor to get it back aftet you rule out the filter you tipically cant get air out without cracking lines

 

[icanfixall]

If you ran out of fuel and cranked on it afterwords you most likely have air in the lines and will have to blead every injetor to get it back aftet you rule out the filter you tipically cant get air out without cracking lines

This comment is not completely correct. Once the engine is running on all 8 cylinders the air has noplace to go but thru the injecters and the return lines. Personally if I'm bleeding air for any reason I crank for 15 seconds. Stop and crack open each easy to reach hard line at the injecters. I listen for the air hiss or look for the fuel wetting. Can't make it harder than that. These are simple fuel systems but upkeep is something many forget to do. An air leak will show up before a fuel leak because the fuel is heavier and as it drains to the tank it sucks in air. Air is smaller than diesel particles.

 

[ford50gt]

Ok, clear hose in the line running from the fuel pump up th the filter inlet is 50% air at idle. Next I clear line the fuel pump inlet.

 

[icanfixall]

Then your sucking in air between the tanks and the lift pump. Time to check all the connections. Tighten up all the clamps or fittings.

 

[Dsl_Dog_Treat]

Since you're in the rust belt, check the drivers side frame rail wher the engine crossmember meets the fuel lines are plastic until that point the turn to metal. It's a common fuel line failure point for those of us who get road seasoning in the winter time.

 

[ford50gt]

Well if I would have replaced the hose between the fuel line and the pump when I changed the filter I would not have started this thread. It looped from the line to the pump and there was a small soft spot about the diameter of a pencil. Did not see it when I checked it last week. All good now for $4.00.