355 new fuel pump helped but needs more still???

Discussion in 'Engine Topic' started by transamman, Aug 8, 2009.

  1. transamman

    transamman Veteran Member

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    my car has afr 195s comp heads, crane 286 energizer cam with 1.6 roller rockers. holley 770, 1 3/4 inch hedman headers, 3500 stall, 4.11 gm 12 bolt posi, accel stock replacement distributor. edlebrock performer fuel pump 110gph at 6ps for 45 dollars from summit,

    it was popping and misfiring from 4000-4500 till i took advice and changed the stock 305 fuel pump out with a edlebrock performer 110gph at 6psi fuel pump,
    I took my car out and it will pull to about 5500 now in first and 4500-5000 in 2nd and in 3rd wont go past 4500 no matter what which is dumb casuse my power really starts coming around there. Could that edlebrock fuel pump just not be enough??? It was the best one i could find with 6psi.

    It runs alot better than it did with the stock fuel pump. about 10 percent of the time when i floor it in 1st it will hesitate and feel like it did before but not nearly as bad.

    or could i be in need of a msd 6al now? this is my first engine i ever built and im 19 so i dont know to much but i think its gotta be the fuel pump not enough, or the spark not enough.

    or i dont know it this could be a problem at all i got ngk heat series 5 plugs in there the hottest they make i think cause my choke was messed up and it was running super rich so i tried to compensate with hotter plugs but now i just opened the choke up all the way with the 3 screws so i dont have that problem anymore. dont know if that has anything to do with it but i was throwing it out there anyway
     
    Last edited: Aug 8, 2009
  2. Damon

    Damon Veteran Member

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    Get a cheap remote fuel pressure gague and mount it where you can see it while you make a run. I duck tape mine to the windshield (temporarily!) and make a run. If you are outrunning the fuel system it will be obvious. Fuel pressure will nose-dive in the upper RPMs followed shortly by the engine nosing over.

    I very much doubt you are in need of a better ignition, assuming yours is in good operating condition. If the fuel pump helped that's probably where the issue lies.

    I'd bet a restriction somewhere in the fuel system- kinked line, clogged filter (don't forget the 'sock' on the tank pickup), obstructed line, etc. I've also found cars that simply can't get enough fuel to the motor no matter how big a mechanical pump is used (this is usually more of a problem only in 1st or 2nd gear, which isn't the problem you are describing).
     
  3. cmonson

    cmonson Veteran Member Gold Member

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    I really doubt a 110GPH pump will have any issue delivering fuel to even a big block to high rpms.

    check your timing.
     
  4. 77 cruiser

    77 cruiser Veteran Member

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    Check the fuel line from tank to pump to make sure there are no kinks or flattened places, also the sock in the tank could be suspect.
     
  5. cmonson

    cmonson Veteran Member Gold Member

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    also, check your fuel filter and ignition module.
     
  6. jroach

    jroach Veteran Member

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    may just need yo run a bigger line go to 3/8 instead of 5/16
     
  7. 80'427

    80'427 Veteran Member

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    This would be my bet
     
  8. transamman

    transamman Veteran Member

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    where do you get these pressure gauges and how much do they run???
    ive done everything besides that it seems so today i gotta get one and try that,

    i took the fuel filter out didnt help tried the timing advanced and retarded, checked the valve springs, the rocker arms have no slop so my lobes are still there, took apart the distributor and it all looks good, even put a new cap and wires on, the secondaries open all the way, oil doesnt have metal in it, its got 3/8 line on it now
    and in park it will rev out so its gotta be a fuel issue cause i assume it takes more gas to make it rev out in gear then nuetral
     
  9. transamman

    transamman Veteran Member

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    im thinking it may be a vacuum leak on my intake manifold does would that make any sense?? i talked to the guy who built my engine and he says it could be a vacuum leak on the intake, or carb base from not being tightened all the way, im gonna put a vacuum gauge on it to see but i got a big cam what should my hg be? like 10 its a 286 advertised duration 106 lsa cam

    i bought my rpm intake off ebay im wondering if it may be wapred thus causing a leak
    im thinking its a vacuum leak because my powerbrakes barely work you can tell there alot more like mechanical brakes then powerbrakes
     
    Last edited: Aug 10, 2009
  10. transamman

    transamman Veteran Member

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    i poured gas around my intake after i shut it down and it bubbled so i know theres air getting in there then i started it up and it barely would run for a few seconds untill all the gas i poured around the intake got sucked in and burnt so its my intake manifold 99.9 percent sure on this now
     

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