Cranks over, but no fuel

Discussion in 'Engine/Drivetrain' started by Henry, Aug 18, 2019.

  1. Henry

    Henry Enthusiast

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    Unfortunately, I've changed A LOT of things on the truck recently so I'm trying to narrow down the culprit.



    What I've changed:
    • Emissions delete
    • Install Weber 32/36 carb.
    • Removed 77 fuel tank
    • Install fuel tank & sending unit from a 78
    • Replaced fuel pump, fuel strainer with new
    • New fuel hoses (rubber)
    • Disconnected harness from engine bay to clean/inspect
    • New battery
    • New fuel
    Overview of what I've tried so far...

    I was ready to try and start the truck after a few years of sitting in the garage. The first thing I did was remove the old tank, and fuel sending unit. I wanted to replace the old tank because it had a good sized dent in it. I had a 78 parts truck that came with a perfect tank. Both the 77 & 78 ran fine the last time it was parked. So before reinstalling the tank I figured I may as was well replace the pump.

    Before attempting to start the truck I disconnected it from the filter, and ran some compressed air through the line from the tank side to blow out any debris, or old fuel. A small amount of fuel came out, but otherwise the lines appear to be good. I wanted to make sure fuel was running through the lines before I reconnected it to the filter, and tried starting the engine.

    I also made sure the engine had a fresh oil change and was filled to the correct level. The engine turns over but there is no fuel coming from the line. As a test, I've disconnected the oil pressure wire to see if the sensor is bad, but it didn't make any difference. I put about 4.5 gallons of fresh fuel in the tank.

    1. Should the pump prime in the 'ON' position, or only when cranking over the engine? From my understanding it won't send fuel until oil pressure builds.
    2. I currently do not have the electric choke on the weber connected. Would this cause an issue?
    3. Where should I go from here?

    Thanks in advance for any help you guys can provide.
     
  2. jetas

    jetas Grand Toyotaholic

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    Check the fuses and relays for the fuel pump

    And make sure you dont have the fuel lines backwards lol. And id definitely hook up the carb completely.
     
  3. Henry

    Henry Enthusiast

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    At the moment I have both lines routed into a plastic bottle.

    Update: I wired the pump directly to the battery (for testing purposes), and it does turn on and pumps fuel.

    So, it's either the resistor (pass side engine bay), or the fuel pump replay (under the dash).

    At least it's some kind of progress
     
  4. Henry

    Henry Enthusiast

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    fuel pump resistor tested at 1.7ohms. I've been told anything above 1.6 would mean the resistor is bad. Hopefully my reading wasn't 100% correct and the resistor is fine.

    I guess the next step would be to eliminate both of these things from the system and see if that fixes it?
     
  5. Henry

    Henry Enthusiast

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    I did noticed the cigarette light fuse was blown. I could be wrong, but I can't imagine this would be the issue. I'll need to figure this out as well.
     

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