[Jeffy 92]

I thought my electric fuel pump had a check valve in it, but maybe not. Is it possible to buy an in-line fuel check valve so I can stop this cavitation? -Jeffy.

 

[1dieselman]

You can install a check valve but shouldn't have to, Is the return line from the fuel filter to the #1 injector hooked up? A little more info on whats happening would help.

 

[Jeffy 92]

Yes, the line is connected. A friend recommended purging the line at the injection pump, then after it's running, purge each line at the injectors- he thinks that will eliminate the rest of my problems. I think it is possible to have a suction leak at the line going from the lift pump to the filter manifold, since at the manifold it has a rubber compression seal inside the b-nut. Maybe I'll re pack it just to be sure. -Jeffy.

 

[1dieselman]

Your electric pump is down on the frame just in front of the tank selector valve correct? If your return line from the filter head is hooked up there should be no reason to purge anything. What are the rest of your problems? Do you still have the lift pump hooked in line using the electric pump?

 

[Jeffy 92]

I do have the line from the filter to the #1 injector connected, but is there another return line? These hoses are old and all need to be replaced. I purge every thing before starting but it seems like the fuel drains back after the truck sits turned off. The fuel filter is about half full. I found that I had caused a leak by adjusting the injector pump timing, and had loosened the fuel supply line in the process. I just discovered that this morning(what an idiot!). None the less, I still have an air leak which also affects over the road driving. I will try bleeding everything again, and hope I just wasn't thorough enough last time. -Jeffy.

 

[1dieselman]

How long since you have replaced the return lines, tees and o-rings? After you get all the injector tops clean and dry and you drive it is there any wetness around the fuel return line tee's. If there is get a return line kit (can be found for about $25 online) . Check the fuel priming valve (looks like tire valve) on the filter head, if its missing it put a good quality cap on it. You didn't say if your lift pump is still hooked up. If it is and your using an electric pump having the lift pump still inline is a real bad ideal. If the diaphragm on the lift pump ruptures the electric pump will fill your crankcase full of diesel fuel in a short amount of time. If your electric pump is working right it should fill your filter and push any air out through the return line in less time than it takes your glow plugs to cycle.

 

[Jeffy 92]

My original lift pump is not part of the fuel system any more, only the electric pump. I have no fuel leakage, but when I remove the cap from the priming valve, there is fuel wetness present. The cap is the type of brass with rubber seal insert used on military airplane tires. I am suspecting the core needs to be replaced. After I drove it last, I bled the injector lines again, since I had an incident of no response to throttle input while climbing a grade. -Jeffy.

 

[1dieselman]

I would check fuel pressure 4-6 lbs should be good, Has the pump timing been messed with, and how about has the fuel been turned up.Does the truck ever black smoke.

 

[Plywood]

I have discovered air leak possiblilty number 1834.
Mine is leaking where the fuel filter heater wire plugs in.
It is a plastic deal with a copper looking electrode coming out, looks like it is leaking where the electrode comes through the plastic.

 

[cdnsarguy]

Jeffy make sure the electrical pump is operating when you go for a start......not just key on. Check the connections of the Epump to fuel lines too..... If the return lines are grey they are OEM replace them ASAP this will ensure the problem is not on them.

Check out....... Ford diesel 6.9 7.3 IDI look for the leak points on the filter and other areas. If you need a return line/injector install kit then check online.

Diesel Parts :: Fuel Injectors, Fuel Pumps and more for Ford, GM, Dodge Cummins, International and more
http://shop.dieselpage.com/main.sc

There are other places too..... ensure you get the right set.

 

[Jeffy 92]

Thanks once again for all the tips, always educational!

I replaced the priming valve core at the filter. it's the same thing you'll find in your wheels. Mine wasn't very tight, but I replaced the core anyway, a bit tighter. Today the truck ran well without any more air bleeding. If bleeding should become necessary, the electric lift pump makes the process easier and a 1-man job. To other non-experts like myself: make sure there is fuel pumping before depressing the priming valve, or you'll just be letting more air in! Thank you experts for helping me with this problem. It seems like I might not need a injection pump just yet, but if it weren't for your advise I'd probably had bought one unnecessarily. -Jeffy.