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Motor running like crap

Discussion in 'The Garage' started by fordeater, Sep 1, 2004.

  1. fordeater

    fordeater 1/2 ton status Premium Member

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    Okay, i put the NWMP 43 gallon gas tank in my blazer in july. Everything went fine until i filled the tank up all the way for the first time. Then the blazer ran like crap for a few weeks. It wouldn't idle, could barely get it to run the 2 miles to work and back. Then, after a week or so, it ran fine. Well, the other day, i filled it up again. It started doing the same crap. It seems like its not getting fuel, but then it smokes really bad, maybe like too much fuel. It only does it when the gas tank is full though, so i'm very confused. Anybody have any ideas?
     
  2. stretch67

    stretch67 1/2 ton status

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    tank venting maybe? does it use a vented cap?
     
  3. kennyw

    kennyw N9PHW Premium Member

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    Sounds like a vent problem starving the fuel pump. Make sure you have a vent line or use a vented cap /forums/images/graemlins/thumb.gif
     
  4. fordeater

    fordeater 1/2 ton status Premium Member

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    its got a vent line on it. It just doesn't make sense to me that it only does it when the tank is full.
     
  5. diesel4me

    diesel4me 1 ton status Premium Member

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    If all the emission hoses are still intact,it might be the purge valve on the charcoal canister allowing raw fuel to be sucked into the engine through its vacuum hoses--would be more likely to do it when its right up full. /forums/images/graemlins/crazy.gifDont know why it would do this with the new tank,and not the old one /forums/images/graemlins/dunno.gifmaybe the hose routing is different?or does it use the original sening unit?. /forums/images/graemlins/thinking.gif You should notice a strong odor of gas near the canister if its the purge valve doing this,maybe even gas leaking out of it. /forums/images/graemlins/yikes.gif
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    I accidentally hooked the breather line directly to my carb one time in my car, and never had a problem with it. That was probably with 5 years of driving.

    Of course, never actually checked to see whether it was ported or full manifold vacuum.
     

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