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Air Leaks

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Old 12-30-2011, 11:35 AM
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Air Leaks

Still having cold start problems! I assume it's an air leak problem because all of the other parts have been replaced:
-8 new Beru Plugs
-New Controller
-New GP wiring harness
-New Injection Pump
-New Starter
-New fuel filter
-New O-rings caps and soft fuel lines.
-New vibra seals at the hard lines.

When the truck sits overnight, you have to crank and crank till it starts. When it does finally start, its starts with a high RPM and a cloud of smoke. Then the RPM's fall back to something like 7 or 8 hundred. Throughout the remainder of the day, it will start and run perfectly. I noticed when replacing the vibra seals, both of the hard fuel lines to and from the filter we empty. I have not checked them since replacing those seals 2-days ago. There's not visible fuel leaks anywhere. I removed the return line that goes back to the fuel filter and plugged both the hose and the filter housing. This made no difference.
 
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Old 12-30-2011, 11:56 AM
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The return line caps sometimes have a rough edge and might have knicked one of the o rings on the injector. Are they viton o rings that you used?
 
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Old 12-30-2011, 12:08 PM
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It was a Stynadyne (spelling?) kit and I lubricated them with vaseline. Also, no visible leaks at any of the injectors.
 
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Old 12-30-2011, 12:24 PM
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Ok i just went through this myself. If you replaced all the o rings on the injectors, and are sure you did not get any of the old ones mixed up with the new ones, all your soft return lines are replaced, i would check the hard line that goes in between your fuel filter and your injection pump . On that line there are 2 cylandrical o ring things about 3/8" long and 1/4" diameter (are they called vibra seals, not sure) get the part from ford or from an injector shop before you take it apart they are probably rotten, when i took mine apart they desinigrated and there was no salvaging them, so make sure you have them before taking it apart. i would bet that is where your problem is.
 
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Old 12-30-2011, 12:30 PM
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Yep, I replaced those just the other day and I did get them from FORD. The old ones were really hard, I had to cut them off the steel fuel line. I used vasoline to lubricate the new seal during installation. At the time, I was convinced they would solve the problem because the old seals looked really bad however the next morning, same thing.

Oh I forgot to mention on the first email I also replaced:
-Both batteries
-New injectors
-and it has an electric (holley RED) fuel pump.
 
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Old 12-30-2011, 12:31 PM
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If I were you I would replace the lift pump when the reids get week in them it will alow fule to drain back to the tank I've had leaking injector caps for a while then it started taking a while to start in the morning replaced the lift pump and its fine.
 
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Old 12-30-2011, 12:35 PM
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I'm curious about the check valve in the filter housing? Could the fact that I removed the fule line and both the housing and the line create a problem? If that little valve doesn't work, could that create a problem? I've considered ordering a new one FORD pn# E9TZ-9K061-A. Does anyone have an opinion regarding the usefulness of this valve? Should I replace it or is it better off plugged?
 
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Old 12-30-2011, 12:49 PM
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I would agree with George if you replaced everything else a $35 lift pump is a drop in the bucket just replace it and see if that works, not sure about the check valve.
 
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Old 12-30-2011, 12:51 PM
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Lift pump was eliminated years ago. It now has an electric (Holley Red) fuel pump.
 
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Old 12-30-2011, 01:51 PM
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If you have an electrtic pump it should self prime the system I would check the pump you're useing and make sure it is working properly also check the lines befor the pump they may be leting air in.
 
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Old 12-30-2011, 01:51 PM
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Where is your fuel pump located?
 
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Old 12-30-2011, 01:54 PM
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Just reread your original post when you start it are you holding the throtle half way down?
 
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Old 12-30-2011, 02:04 PM
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I've considered eliminating the entire factory fuel filter, filter housing, and the "none standard" steel fuel lines (the one with the vibra seals). And installing a FRAM HPG-1 fuel filter. Replacement filter is $6.00 vs $30.00 for the factory one. Using this filter would require plumbing a fuel line from the pump to the filter, then another from the filter to the injection pump. Last, I'm considering removing the hard (steel) fuel line that goes from the injection pump back along the driverside of the engine to a Tee near the fire wall, replace it with a simple piece of rubber fuel line and brass Tee from the auto parts store.
The only reason I have not done this so far is because I'll lose the fuel heater (forgot to mention I also bought a new one of these), the water in fuel sensor, and the schrader valve for bleeding air. However, if everything works as it should, you don't really need any of that stuff!
 
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Old 12-30-2011, 02:12 PM
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-Electric pump is mounted to the frame 6" from the tank selector valve.
-I do not hold the pedal half way during starting......... never did that. Is that a required / normal way this truck should be started?
 
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Old 12-30-2011, 02:40 PM
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I personally never have held the pedal but others do. You do seem to have an air intrusion problem. Remember that air can get in with out any fuel ever leaking out. Is your water seperator built into the fuel filter or on the firewall? The one on the firewall is known to allow air back into the system at the drain. Also, all those vibra seals are there because of the vibration of a diesel while running. The fitting on the injection pump is also not standard. It is made to be sealed by that rubber not a flair nut type.
 


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