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carb/fuel problem

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by GUMBY, Jul 2, 2002.

  1. GUMBY

    GUMBY Registered Member

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    I have a quadrajet on a mid '80s 454 with a mechanical external fuel pump. I cranked it up like normal and it ran for a couple of minutes and then died suddenly. I tried to restart it and it would start but then immediately die again. I checked if the carb was getting fuel and when I would manually pump the accelerator under the hood, it would spray like normal. Even though I can pump the pedal a few times and it would start up, it will not keep running. I tried pouring fuel directly into the carb and again it would crank but wouldn't keep running. I've tried pumping the accelerator right after it cranks but it will not keep running. If fuel will squirt from the jets, why will it not keep running? I assumed if the carb will squirt fuel from the jets then the fuel pump must be working. Could the fuel pump still be causing this or is it the carb?

    Thanks
     
  2. Thunder

    Thunder 3/4 ton status

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    Dont think it is carb or fuel problem.
    Sounds like the fuseable link/resistor wire for your ignition is bad.
    When the fuseable link goes out. The engine will start and run but will die as soon as the ignition switch is released from the start position to on.
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    I think you are right, not a fuel pump problem.

    I really can't think of anything that would be so "intermittent" as you describe. Running then dying...ignition modules can be kind of freaky, but still, to be that consistent seems odd. As was mentioned, something being screwed up and overheating quickly might do it.

    I wouldn't bank on fusible links, my reasonning being you only have one or two fusible links, (trucks are two IIRC) if one of them goes bad, and since ALL fuse panel power is through them, you'd lose all power to the vehicle if that were the case...it couldn't even crank.

    I really can't remember for sure, but theres a junction block on the firewall on my truck for them...but if theres no junction block, headlights are seperate of the other electrical items, so if one fusible link dies but not the other, then if the headlights work, the other link is dead, if they don't work, you just won't have headlights. Clear as mud?

    Like I said though, I believe trucks have a junction block, which *probably* means that both fusible links "join together" and if you lose power, you've lost both of them.

    Either way, if it cranks fine at all times, I'd say no, it isn't a fusible link.
     
  4. Thunder

    Thunder 3/4 ton status

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    OOPs yur right Dyeagr. Shouldn't be fuseable link and no resistor wire on chevys. Senility is setting in early /forums/images/icons/crazy.gif I was thinking of fords with the resistor wire to the coil /forums/images/icons/confused.gif

    Anyhow back to the problem.I think a few brain cells are still functioning /forums/images/icons/smile.gif
    It could be the module in the distributor.
    Or
    Turn the ignition switch to on and see if you are getting 12 volts to the coil. Maby there is a problem with the ignition switch or primary wiring.
     
  5. GUMBY

    GUMBY Registered Member

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    Thanks for the suggestions. I'll check them out.
     
  6. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    Well if you're an adventurous fellow, you could do this. Take a piece of 10 gauge wire and clip on a female stlye connector on one end. Unplug the pink wire on the distributor that goes the terminal labeled "Bat". Plug the wire you made into that. Then run that wire over to the positive lead on your battery. That sucker will get 12v all the time if it likes it or not. Now to stop it, you'll have to unplug that wire. Be careful while doing it and don't ground the end out anything and you should be fine.
     
  7. Khi5in

    Khi5in Registered Member

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    I am a mechanic and had a customer with the same problem on a camaro. I went out of my mind trying to fix this without thrpwing parts at it like a lot of mechanics do. Thunder was on the right track it is an ignition problem but not the fusable link. not a module but the pickup in the distibutor. You see key on sends voltage to the coil and then to the module. the pickup then sends the spark to the cap. the bad pickup will cause it to lose ground so it will seem like a module problem but it is losing a gound before the module wich will act like a bad module. I would put a reman distributor in it to save time and money on individual parts.
     

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