Help me ID fuel lines on 83 K5

[Mastiff]

I have three lines going to my gas tank. Two of them dump gas on me and one doesn't (if I disconnect the rubber part). I think the one that doesn't, "C", is the one that used to go to the charcoal cannister. How can I tell between "A" and "B" which is from the tank and which is the return? "B" is larger diameter, but "A" dumps gas on me from the tank side (I didn't notice which side the fuel was coming from with "A").

I'm installing my TBI kit and need to splice the fuel pump into the correct line from the tank. I have a carb right now, but there is a return line from the fuel pump.

 

[GMCLegacy]

well on a truck the line that is in the middle of the 3 is the suction line at the pickup in the tank IIRC. im not sure on a k5, i would assume the same, but my luck isnt always the greatest.

it wouldnt take much to through it inbetween one of those sections of hard line and run a temp 12v power wire to the pump to see if it pulls gas from the tank.

 

[Mastiff]

I'm not sure what the return line does once it gets in the tank. Are you sure I wouldn't get any gas from it if I pumped on it? It's weird that gas comes out from both. I guess I could get a container and wait, maybe the return line is just spilling out what's left in the line. /forums/images/graemlins/dunno.gif

 

[Mastiff]

Anyone?

 

[jjlaughner]

the 3/8 line (the big one) is the fuel to
the 5/16 line is the return
the one that doesn't leak fuel when unhooked would be the vapor line to the canistar up front

 

[CyberSniper]

The smaller line that goes to the driver's side is the charcoal canister. The other small one is the return. The big line is the actual fuel line. If you were using a mechanical pump the return will have petrol in it.

 

[Mastiff]

Thanks dudes. That's what I was going to go with but the confirmation makes me feel better. /forums/images/graemlins/thumb.gif