87 D150 Slant fuel lines?

[JESMAT5243]

I have an 87 D150 w/ slant six. On the frame I have 3 lines coming from fuel tank. One is the supply for the pump, one goes to charcoal canister. What is the third one from. Previous owner has it plugged off with a bolt and band clamp. I’m sure this needs to go somewhere, but where is that somewhere? Thanks in advance.

 

[JESMAT5243]

Ok I think I have figured out that one is a return line that should be connected to the stock fuel filter that has a provision for it. I currently have an aftermarket in line filter that does not have this connection. Do I need to utilize this return line or can I leave it plugged? Also when I disconnected what I believe is the vent line from the vacuum canister a considerable amount of fuel came out. Is this normal or am I looking at this all wrong??

 

[7mopar]

Ok are all the vacuum lines connected to the canister? And no it is not normal to have raw fuel in the canister. There should be a vacuum line diagram in the engine compartment if the proper lines are not connected to the canister fumes are vented from the carb with the engine shut off. When the engine starts there is a vacuum valve on top of the canister that is supposed to only allowing the engine to suck the fumes back threw the carb at the proper time.

I am guessing the fuel you are seeing was from built up fuel fumes. Fumes are vaporized fuel.

 

[JESMAT5243]

Everything was connected per the hood diagram. I’m pretty much sold that the extra line is a return that originally hooked to the factory fuel filter. It just seems odd that that much fuel would be from fumes. It almost seems as though the tan were pressurized and sending fuel where it should not have been. Putting a new carb on it this weekend. I will double check all the lines to make sure I didn’t hook it up wrong. Thanks for the reply and help.

 

[7mopar]

There should be no fluid fuel line to the vapor can. Just a vapor line from the carb bowl vent and vacuum lines.
The fuel line to the carb only had the return line to the tank to vent vapor from the feed line.

 

[JESMAT5243]

The vacuum diagram shows a line that goes from canister to fuel tank, as well as the bowl vent to the canister. There was fuel in the line from canister to tank. Why would this be if it is just a vapor vent? The line that I believe should go to fuel filter is currently plugged.

 

[7mopar]

Has someone blocked the line from canister to tank? It should only be transporting fuel fumes from the tank and not liquid fuel. No liquid fuel should be being drawn into the canister. It sounds like the valve on top of the canister may have a malfunction and engine vacuum maybe drawing fuel from the tank when the tank is full. This is why it is important to stop fueling when the pump shuts off instead of trying to feed those last pints of fuel into the tank. This is the same reason on newer vehicles and evac error will show up. Not sure if this is your case but just exploring possibilities.

 

[JESMAT5243]

Line is not blocked. Tank hasn’t been past half since engine was replaced and lines reconnected. Carb is being replaced this weekend. After reading your post I think maybe I have vacuum source connected to the wrong port on canister causing vacuum to the wrong places, or.. valve is faulty. I’m going to look further into it tonight. I will post what I find. Thanks to all for advice.