Fuel filler keeps backing up... Ideas?

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da_raabi

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So I had to disable my dual tank setup (stock 2 tanks) a couple of days ago because the fuel tank selector valve went south. I simply bypassed it and hooked up the fuel line and return line from the front directly to the passenger side tank. Truck gets fuel fine (although the choke is broke... again) For some reason though the passenger side tank does not like to fill, the fuel keeps backing up in the filler neck and then sloshing out while filling. Any ideas on why this would be happening? I'm thinking maybe a vent is clogged? Thoughts?
 

Boone83K10

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the angles on the filler neck aren't that great. some people have to feather the gas pump all the time. pull it back some, don't shove it all the way in and fill it up. if that doesn't work, then start looking at the return line on the filler neck. my question is why didn't you just buy a new selector valve? they aren't very expensive and pretty easy to put on.
 

da_raabi

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It's my daily driver and I needed it to get to work. I already took 2 days off to figure out what the problem was, so by the time I figured out it was the selector I was in a hurry to get it fixed.

As far as the filler I'm glad to hear its not just me though, I guess I'll just have to take my time filling. I wonder if older gas station pumps didn't put out as much pressure? I can't see this "feature" being normal when these trucks were brand new.
 

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Happens to me too. Just back the pump a little, but you have to listen for the tank to fill. If you leave the pump running solo, it till disengage too late and splash some gas on your fender.
 

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Sometimes rotating the nozzle a little so the fuel spins down the filler helps, like how a toilet flushes LOL. I have to do that with mine.
 

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Yeah same here, back it out just a bit and sometimes I twist it like '89 said.
 

Boone83K10

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I didn't say mine did it.... in fact I can put it on full blast and it will click off perfectly fine. Funny how it works well on one and not another. Then again I have metal piping for my filler neck/return line with small sections of hoses, and it has GM stamping on the pipes which seems odd, not like others have said with just rubber hosing.
 

da_raabi

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Ok I'm starting to really lose it here. I got 3 gallons in the tank in about 15 minutes. If I go full bore it pours back out like a fountain, I feel bad because I have to wipe up all the fuel and toss it in the gas station garbage. Is there a good reason why this would suddenly start happening? It never did it before I bypassed the switching valve. Would that somehow effect the filling?
 

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Did you do anything that could have led to the fill hose getting kinked? Either that or someone stuck something in your tank. That's all that makes sense to me at this point. :(
 

da_raabi

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Nope, never touched the fill hose. In fact I have a locking fill cap on there to keep anyone from messing with it.
 

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I have to pretty much flip the nozzle upside down on my K10 at most pumps :shrug:
 

da_raabi

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Hmm I debated trying that, I just didn't want to make a mess. I'll have to suck it up and give it a go. I'll probably get some pretty funny looks about it!
 

Stroked

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People do tend to look at you funny :drunk:
 

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You definitely have a venting problem. I would just start investigating the vent line going to from the filler to the tank. If there is a low spot in that line it can fill with fuel and block any venting action.

I also noticed just this week I parked at one of the pumps that was on a slight incline tilting the truck away from the pump and it filled quite nicely. Didn't pop the trigger at all on full blast until it was full. So I have a favorite fueling spot for right now.
 

da_raabi

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You definitely have a venting problem. I would just start investigating the vent line going to from the filler to the tank. If there is a low spot in that line it can fill with fuel and block any venting action.

I also noticed just this week I parked at one of the pumps that was on a slight incline tilting the truck away from the pump and it filled quite nicely. Didn't pop the trigger at all on full blast until it was full. So I have a favorite fueling spot for right now.

Ok looks like I've got something to take a look at then. If that dont work I might bust out my jack nascar style and lift the one side while I pump lol!
 

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