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1979 Cj5 Fuel System

Discussion in 'Intermediate CJ-5/6/7/8' started by DanStew, Sep 28, 2020.

  1. Sep 28, 2020
    DanStew

    DanStew Preowned Merkin salesman Staff Member

    Lexington, South...
    Joined:
    Sep 22, 2002
    Messages:
    4,585
    I am just about there to start the Jeep. BUT I need to address the fuel system. I am a bit scared of the critters i may find under it but i did a good pressure wash to hopefully get rid of them. So far I found a green nylon hose that extends from the rear to the front, and from the diagram it goes to the rollover check valve. I found teh valve and it crumbled in my hands, so i am not gonna use it. I see i still have the Liquid Check valve in the back, but it looks filthy and not sure of its condition. So before i drop the tank I have a few questions.

    1. Is there a return line to the tank? The diagram shows none, but the engine has one of those fuel filters that has a return line. It was plugged but i didnt know if it was the correct filter.

    2. If the liquid check valve is bad, can i just run a return line to one of those vent lines that goes to the check valve?

    I dont care much for originality, but i know that some motors needs the return line to play nice. This is the 304.
     
    DanStew, Sep 28, 2020
    #1
  2. Sep 28, 2020
    Chuck

    Chuck Sponsor

    Southshore Ma
    Joined:
    Sep 19, 2004
    Messages:
    1,463
    1. Is there a return line to the tank? The diagram shows none, but the engine has one of those fuel filters that has a return line. It was plugged but i didnt know if it was the correct filter.

    Yes, filter has 2 outlets on one side and one on the other. One nipple side is tank feed, on the two nipple side, bottom goes to carb, the top is the return line to the top of the tank sending unit. The filter must be positioned with the return line at 12 o'clock to work properly.

    2. If the liquid check valve is bad, can i just run a return line to one of those vent lines that goes to the check valve?

    You can buy an aftermarket liquid check valve or used one from another vehicle. The tank side vent has 2 nipples both go to the liquid check valve, then one travels to the roll over valve, then to the charcoal canister. You could cap one of the two side vents at the tank then run one vent line to the charcoal canister bypassing both values. The charcoal canister needs vacuum typically air drawn through the air filter housing.
     
    Last edited: Sep 29, 2020
    Chuck, Sep 28, 2020
    #2
    DanStew likes this.
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