Chasing air intrusion, problem with stuck fittings on fuel selector valve

[joel1847]

Still chasing air intrusion and am currently still unable to use rear tank. Upon switching to rear tank I get surging and a slow but steady loss of power. Switch back to the front tank and power comes back within 1/8-1/4 mile. So that should mean it's from the FSV back to the rear tank. I finally get some time to work on the truck and I get the clip off of one rear tank line, but the fitting will not come loose at all. I don't want to break the valve but I don't have a lot of slack in the lines nor do I have a lot of room to work with. Would it be wise to go ahead a cut the main supply and return lines coming from and to the engine and then insert a fuel line repair kit so I can get some slack to work on the lines on the valve? I may go with manual valves later, but I can't afford to have the truck down right now.

Thanks for the help

Joel
norcal

 

[79jasper]

Did you pull the clips?

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[madpogue]

Does the hose rotate on the fitting, now that the clip is off?

 

[joel1847]

Yes i got the clip off and no it didn't rotate very much if at all. For all I know, these are original.

 

[joel1847]

I was only able to work on the one line before I had to quit so the others might be okay. If I can get the FSV to move a bit so i can get both hands on it, then i will replace all of the o rings.

 

[79jasper]

Just keep working it. Try getting it to twist. May break the seal.

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[joel1847]

Got that fitting loose and the female side has 2 o-rings in it. Brown in color (vitons?) So how do you replace those two O rings? Cut the fitting and replace it?

 

[79jasper]

Get a pick and pull them out.

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[joel1847]

That was pleasant.

Replaced all 4 O rings on the FSV for the rear tank and took her for a drive and it still did the same thing. Ran good, then started surging, complete with some really nice power, then power loss again. Died around the corner from the house, tried to start it and the starter hung up and spun a flat spot on the flywheel, so had the wife tow me home.

Starter is okay though. So this being an automatic, I guess I get to find a breaker bar and a socket that fits the crankshaft...

 

[79jasper]

I believe the connections at the tank may have orings also. Harder to see in there with the quick disconnects.
There's also the chance that the selector valve could have a problem.
Or something in the line.

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[joel1847]

I lost the sending unit on the front tank a couple weeks ago so I"m trying not to get too upset at the truck. I think I'll switch over to manual valves next payday. Electric is nice, but something to be said for manual stuff when you have to troubleshoot. I"m also half tempted to replace the rear tank with a 38 gallon one and be done with it.

One thing I wonder about though. I blew air through the lines once I disconnected them. I could hear air bubbling in the tank when I purged the return line, but I didn't hear anything when I purged the main feed line. Not sure what that means. If the tank is too full, can it cause problems? Seemed odd.

Thanks for the help man.

Joel

 

[79jasper]

Sounds like you had them reversed. Unless the feed line is broke off, or has a hole in it up higher than the fuel level.

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[joel1847]

The rear tank worked fine for several months with no issues so I don't think it was reversed. Could be a hole up near the top. Something else, when the truck died, there was plenty of fuel in the fuel filters (gotta love goldenrod). It was doing this before I added the extra fuel filters, so that isn't it either. I may need to drop the rear tank and see.

Joel

 

[79jasper]

That's what I'd do. Or pull the bed depending how much fuel is in it.

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[icanfixall]

Honestly your issues sounds like there is crap stuck in the fuel tank switching valve. Have not read if you have the broken shower head suction piece in that bad tank. If you did and repaired it by adding 3 inches of rubber hose to reach the bottom of the tank you probably sucked up some small pieces and have caused that tank plugged up in the FSS valve. That valve can be removed and opened up but you will need some machine screws to close it up again. They are factory riveted together. They drill out fine. Several members have done this repair and found all kinds of "stuff plugging or blocking the FSS from switching completely.