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Edelbrock Running Rich

Discussion in 'Intermediate CJ-5/6/7/8' started by Tree cutter 08, May 24, 2019.

  1. May 24, 2019
    Tree cutter 08

    Tree cutter 08 Member

    Cleveland ga
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    Just installed a fuel pressure regulator this morning to make sure I'm under the 6.5 psi edelEdelb recomends. I'm still running rich. Timings set good and I've adjusted the idel mixture. Runs great and strong idles good it just loads up. Haven't fouled any plugs yet. Also running a DUI distibitor and plugs are gapped at 55 like they recommend. Any Edelbrock experts here?
     
  2. May 24, 2019
    47v6

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    Is this 600 CFM carb on a v6 225?
     
  3. May 24, 2019
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    As mentioned above in terms of size, it would be helpful to know the size of the carb (cfm) as well as what engine its feeding. Its not uncommon for too large of a carb designed for a v8 to find its way onto smaller v6 (such as the 225v6). Assuming you have a well matched carb size to engine size: I am not familiar with edelbrock carbs, but for many other carbs, the main jets are not 'adjustable' in the carb, but rather are a fixed size and need to removed and replace with different size if necessary - you may need to go to smaller jets.
     
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  4. May 24, 2019
    Tree cutter 08

    Tree cutter 08 Member

    Cleveland ga
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    Sorry about that, it's a 500cfm on a 304
     
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  5. May 24, 2019
    Keys5a

    Keys5a Sponsor

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    The Edelbrock carbs are the new version of what was originally a Carter AFB from the late 1950's up through the 1970's. These carbs have lots of adjustability via changing jets and metering rods. The top of the bowl has to be removed to access these parts, and you need to have a selection of both jets and metering rods to make meaningful adjustments. You also have to know what sizes your starting with as a baseline. It sounds like your jets are too big, or the metering rods too skinny.
    -Donny
     
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  6. May 24, 2019
    53A1

    53A1 Member

    Kern Co. Ca.
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  7. May 24, 2019
    Tree cutter 08

    Tree cutter 08 Member

    Cleveland ga
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    Just ordered a kit. Thanks !
     
  8. May 24, 2019
    colojeepguy

    colojeepguy Colorado Springs

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    Wow small world, I have a good friend who lives in Cleveland GA :)
    I'm kinda surprised you're running so rich, the 1404 is a good match for your engine.
    Use this jetting chart and you should be able to get it dialed in.
    1404
     
  9. May 24, 2019
    Tree cutter 08

    Tree cutter 08 Member

    Cleveland ga
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    Yeah I was sorta thinking it would be a good match for the 304. Runs like a sewing machine but awful rich. The kit will be in in the am so I'll try it tomorrow hopefully.
     
  10. May 24, 2019
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Was a Rochester QuadraJet Expert back in HS / Technical School . The q jet is a much better carb for off roading . Your going to need more mods if your going off road. Like Donny said, metering rod adjustments , ect, ect. There's another thread with a You Tube video of the EdelBrock Modifications.

    When you say that " it just loads up ": but the Plugs are not fouling , what do you mean ?. Also , do you know how your 304 runs under Load ? Is your EdelBrock new , from the factory for your engine ?
    I'm glad you got the FPR , cause I'm leaning towards you simply turning your fuel pressure to 5.5 PSI., EdelBrocks recommended FP, for the road. See if that helps the rich condition. When you go on the trail , you have to turn down your Fuel pressure to like 2.5 or so, 'Cuz the EdelBrocks are very prone to spilli'n over & flooding engines.
    On another thought with your HEI distributor, you should be running some premium 8 MM plug wires & a a good spark plug. You may want to close that gap to say, 0.45 . it helps at Idle burn that fuel quicker & helps with ' Loading Up '
     
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  11. May 24, 2019
    Tree cutter 08

    Tree cutter 08 Member

    Cleveland ga
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    Seems like it runs great on the road and under load. When I say loading up, after extended idle or low rpm cruising you can almost hear it, then rev it up and clean it out and runs smooth again. Strong unburned fuel smell to. Carb is new with around 250 miles on it and the motor. Fuel pressure is running at 5.5 when cold and drops to around 3 or so when warm.
     
  12. May 24, 2019
    Tree cutter 08

    Tree cutter 08 Member

    Cleveland ga
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    Also using the DUI live wires that are 8mm. They recommend gaping at .50 to 55.
     
  13. May 24, 2019
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Your FP should stay consistent.... engine temp does / should not affect FP.
     
  14. May 24, 2019
    Tree cutter 08

    Tree cutter 08 Member

    Cleveland ga
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    Reckon why the change? I did notice it will build back up to 5 to 6 once engine is off.
     
  15. May 24, 2019
    Lockman

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    Do You have a fuel return line (to tank) on your fuel filter setup ? if you do , The return line should be facing in the " UP ' Position. It also may explain the FP drop when warm. However, it is only designed to return fuel to the tank during high engine temps .
     
  16. May 24, 2019
    Tree cutter 08

    Tree cutter 08 Member

    Cleveland ga
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    No return line.
     
  17. May 24, 2019
    Chilly

    Chilly Active Member

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    I'll not bash Edelbrocks because I dont have first hand knowledge. I wont have first hand knowledge because I've read so many complaints about them. Many issues were finally resolved by a different brand of carb. If you cant sort it out consider trying some other carb?
     
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  18. May 24, 2019
    colojeepguy

    colojeepguy Colorado Springs

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    In my experience (selling them and installing them as well as using them on my own vehicle) they're an excellent street carb, but not well suited for off road use.
     
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  19. May 25, 2019
    Lockman

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    The 1975 CJ5 V8's did . Factory. You may want to look into that further, since it pertains to your fuel problem ?

    BTW, Most of my reply's are info from my 1975 TSM. My '75 has a custom engine & 'tranny from an ' 84 Buick GN Turbo V6 Hot Air. Of Course, much different than the carb's, Fueling supply is one of the important things that I have to keep up on , in order to run correctly & tune. OEM parts are very rare, iwith most discontinued years ago.
    Love my 1975 CJ5 . Rosie's is as strong as an OX, 95 % Cherry and the last one that I'll own, for sure. Good luck to you.
    Richie----Lockman
     
  20. May 25, 2019
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    My '75 V8 has a return line. The TSM says all Jeep models except 232/258 CJs have one in 1975.

    JeepEmissions1975.png

    That said, I don't think missing the fuel return is making a difference to your carburetor. Instead, I'm thinking the direction Donny pointed you is the right way. No "universal" aftermarket carburetor will perform ideally without tuning to the specific engine.

    Knowing nearly nothing about the AFB/Edelbrock, I gather from the above that it's a tapered needle type of carburetor. The throttle lifts the needles out of the main jets and the gap between the needle and the jet hole determines the mixture. The diameter of these needles sitting in the jets and their local and overall taper determine the mixture over the full range of throttle opening. Seems likely that a poorly tuned carburetor of this type could be too rich at low throttle and perfectly tuned at highway speeds.

    The return system metering is really simple - just an orifice in the fuel filter that allows some of the delivered fuel to return to the fuel tank. I understood it's more about promoting fuel circulation and preventing vapor lock, not so much about engine performance. Might have something to do with the higher under-hood temperatures that came along with leaner mixtures that are associated with a progressively more emissions-tuned engine.

    Unless I missed it, there's nothing in the '75 manual about it except for the notation in the table above. Even the drawings of the fuel tanks don't show return lines. The return lines appear in 1976 in the drawings and the text. From the '76 TSM:

    upload_2019-5-25_8-38-35.png
    upload_2019-5-25_8-38-47.png
     
    Last edited: May 25, 2019
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