670cfm Holley

Discussion in 'Technical' started by TonyS, Apr 25, 2008.

  1. TonyS

    TonyS Member

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    Hi, I have a 1973 302 auto. Grabber. My 302 has a nice hyd. cam ,ProComp Dizzy, Hooker Headers and Highrise. I put a new 670 cfm Vac Secondary Holley with an elect. choke. on about 3 month ago. It has been running great. But today was a bad Marverick Day. It will still start right up ,choke open fully.but it won't go over 2000 rpm in gear. If I rev it sowly in nuetral it will rev past 5000 rpm. I check the timing stedy a 12 btdc, 18 lbs at idle and it rock steady, fuel level will barely spill out the sight hole if you gently rock the car.
     
  2. maverickoutlaw

    maverickoutlaw Member

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    put a new fuel filter on. that is most likely your problem.
     
  3. baddad457

    baddad457 Member

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    And get rid of the choke. You don't need it where you're at.
     
  4. TonyS

    TonyS Member

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    I will pick up a new filter on the way home.

    Thanks
    Tony
     
  5. Matterick

    Matterick Matt Somerville

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    if it could be something in the tank get a clear fuel filter to see :)
     
  6. TheRealDeal

    TheRealDeal Member

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    Hi Tony,
    Are you the guy driving a flat black Mav. ?
     
  7. Thack

    Thack vision advicator

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    I don't know about you but, I like to drive my car. And nothing pisses me off more than a car that stalls at stops before it's completely warmed up. The neighbers would shoot me if I set and warmed it up in the drive way at 5:00 am.

    You will probly say faten the jets......wrong then it will run sluggish when up to temp. Fuel injected cars still run a rich curcuit untill up to temp and they are the pinnicle of efficency. Even though it isn't super cold out here the water is still not at operating temp at start up.

    A properly adjust choke will work great at 30, 50, or 110 degrees
     
  8. baddad457

    baddad457 Member

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    My 570 Street Avenger works fine at all temps with no choke. It's not tuned rich either. The secret is the EFI cam in the 5.0 it's on. I never have to give it a pump shot before starting either. And the spark plugs are two years old. I drive it everyday. Jump in it before daylight, fire it off and drive away. Just like EFI.
     
  9. Thack

    Thack vision advicator

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    Soooooo you don't have 3 holley 250's...............trust me you are fat at 180 degree

    Cheers to the perfect tune :D
     
  10. baddad457

    baddad457 Member

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    This is the 5.0 in my 89 Ranger I'm talking about. Roller 5.0 shortblock, F4TE cam (this is the cam used in the Explorers too) Ported E7 heads, 1.7 Cobra rockers, Ford A321 intake, Holley 570, Crane XR-1 in a reman points distributor, Mallory ProMaster coil. The Explorer cam has virtually no overlap and pulls a high vacuum on fireup, this lets the carb circuits work faster. There's nothing "fat" about the tune, pull the plugs and they look like they came out of the box.(and as I said before, they're two years old) The 331 sixpack also has no choke but does need a couple of pump shots to get her to idle.
     
    Last edited: Apr 26, 2008
  11. TonyS

    TonyS Member

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    Hi, The Real Deal,it a Blue 1972 Grabber. This is what I have done. Put a clear filter on, pulled the needle and seat to check for FOD. It was clean. Pulled the Holley Filters out. Pulled the front Bowl. Check the jets for FOD, they were tight and clean. Re-set the float. Put all back together and started her back up. It still the same. As soon as I hit 2200RPM it noses over. I check the Electric choke, key on 12.5 volts to hot tang on the choke. The choke will stand straight up after about 4.5 minutes. I rev the car and the choke dose not move. I get 2 steady stream of fuel down the carb as soon as I move the throttle. The car had been ruining prefect until The Black Thrusday. Today I'M going to look for a vaccuum leak.
     
  12. baddad457

    baddad457 Member

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    :huh:FOD ? Could be a ruptured powervalve diaphram doing it. Also try disconnecting the choke, wire the butterfly open and drive it and see what it does. What a carb does in the driveway in park is completely different that what happens in actual operation.
     
  13. dkstuck

    dkstuck Member

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    Ignition???
     
  14. TonyS

    TonyS Member

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    Looks like a bad timing chain. Pop the dizzy cap off. Line up tdc on the blancer. Turned the dizzy until the rotor was on #1. Lock down the dizzy ,rotor on # 1 balancer at tdc. Spin the engine around a couple of time. Trun the engine hand until the rotor was at #1, piston at TDC. Look at the timing marks and the blancer was at 21deg TDC. Spin it again this time it was at 15deg, rotor on #1, piston at TDC.. I close up for night. What do you guys think. Thanks for all the info and help.
     
  15. Thack

    Thack vision advicator

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    That sucks that it wasn't the carb or fuel lines much easier to fix.

    BTW FOD=forign object damage nut's bolts dirt ect, aircraft/military term
     

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