Possible air in fuel lines

[mackmack]

Recently swapped a 6.9 into my 88 f super duty. The 7.3 died on me. Bought this 6.9 off a friend of mine I test drove the truck it was in so I know it is a good running engine. I finally got everything together yesterday and was ready to fire her up. I cycled the glow plugs and cranked her over.to my surprise she fired right up. Ran a little rough so I gave her some throttle and she settled out.ran Good for about ten minutes then died.i rechecked all my fuel lines made sure everything was tight.after this I could not get her to start.i seem to have fuel to the injector lines.i finally gave up on it for the day.this morning I went out and did the same thing. She fired right up ran for about ten minutes then died.after that she won't start. What am I missing here. I replaced fuel filter. I have the 7.3 set up for the fuel filter on it. Do I have air in my fuel lines some where.

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[towcat]

the longblock has no effect on the fuel system. 6.9 will work fine in place where a 7.3 once lived. time to put in some PVC hose to watch for air bubbles. I'll see if I have some pics handy. firstly, you need to isolate which bank has the issues and if it's coming from your fuel pump or fsv. also, did you put in a fresh fuel filter and checked to see if the fuel feed line got smashed while installing the motor.
more input necessary

 

[mackmack]

I did put in new fuel filter filled it with fuel before installing it . I will double check fuel line to make sure it didn't get smashed.

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[mackmack]

Well I have found that the steel line that runs from the tank up to the fuel pump was kinked. For some reason there is a piece of rubber fuel hose spliced in the middle of this line where it goes across the cross member. This doesn't seem right to me.my f350 don't have this . Was able to get her start but still having same issues.

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[mackmack]

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[mackmack]

I do have fuel at the Schrader valve on top the fuel filter

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[towcat]

your line got either yanked or smashed.
trace back to the fuel switching valve to see if you have any more damage.

 

[icanfixall]

Might tell us what level the tanks are at. If they are near 1/4 full then you probably are sucking air. The suction line in the tanks has a shower head item on it. That breaks up and falls off. Then the last 1/4 tank of fuel is impossible to suck out because the now too short suction line is at that level. So you end up with holly fuel. Thats fuel you never use.

 

[mackmack]

I'm a little above a quarter tank and it is sitting on a little bit of a hill. I think I will fill the tank before going any further with it. What I can't understand is why if it sits overnight it will start and run for a short period of time then die. What is the best way of bleeding at the injector lines . I have tried cracking all of them then cranking. I have air bubbles on at least two of them . Can't seem to get steady fuel from them. I don't want to burn up my starter.

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[gandalf]

... time to put in some PVC hose to watch for air bubbles. I'll see if I have some pics handy....

Towcat apparently forgot to add a picture. I have one I can put in. I put clear line between the IP and number 2 injector, and another between number 1 injector and the fuel filter. That covers both banks of cylinders.

 

[icanfixall]

Being near 1/4 tank tells me you are sucting air from the tanks. Please add 5 gallons and see how the engine runs.
As for fuel at the injectors. you will never see as much fuel there like what you see at the schrader or when looking down into a carb engine when you pump the throttle. Our idi burns very little fuel per combustion stroke. Best you will see cranking is maybe a drop or two once in a while. No gusher of fuel ever from injectors.

 

[IDIBRONCO]

Here's a possibility. When you switched your engines, did you happen to hook up your timing advance and fuel shut off wires backwards? This would cause your engine to shut off when the fast idle loses power. 10 minutes could be about right. This is a lot easier to do on a 6.2/early 6.5 Chevy, but it could be done on a 6.9/7.3. If your engine starts and runs smooothly for the 10 minutes, this could be your problem.

 

[icanfixall]

The above posting can happen but you end up forcing the female connectors onto the male spade connectors. They are much different sizes just so this can't happen. The large connector is the fuel shutoff nearest the radiator on top of pump and the rear connector is the smaller one for the cold advance circuit.

 

[mackmack]

Well I'm pretty sure I don't have them switched like you said you would have to force them to make that happen. I did try filling the truck with fuel. Now have more then half a tank.

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[franklin2]

I don't think it's a air problem. If that were true, it should have long crank times and be hard to start the next morning. The wiring theory is interesting. What would happen if you put a jumper wire from the battery + to the injection pump to hot wire it. Would it continue to run? Do you have some sort of power problem to the injection pump?