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Holley 94 Tuning Help!

Discussion in 'The Hokey Ass Message Board' started by 48Tom, Oct 3, 2011.

  1. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

    So I just recently completed a rebuild of a Holley 94 carb for my '48 Tudor (thread: http://jalopyjournal.com/forum/showthread.php?t=628575), and I did manage to finally get it started, however I'm not sure it is running as well as it could be.

    I have taken the basic advice of setting the idle screws to 1 1/2 turns, but other than that I really have no clue on tuning this baby.

    Any words of advice or wisdom?

    *Note: When rebuilding the carb, I was unsure of how to set the needle tubes (if they needed to be set at all). Is there anything special I need to do with those???
     
  2. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

  3. railroad
    Joined: Feb 3, 2010
    Posts: 242

    railroad
    Member

    After the engine has warmed up, you can adjust the idle screws to get the smoothest idle or highest manifold vacuum reading. If the idle speed gets too high with the best adjustment, lower the idle speed with the screw on the side linkage. If you are driving it you should be able to tell if the rest of the carb is functioning properly.

    good luck,
     
  4. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    Quick way. Idle screw in till it starts to drop out, then out 1/2 to 1 turn. repeat.

    Vacuum gauge as mention is a great way to go. Can tell you a bunch about the condition of the engine too.
     

  5. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    Hey just looked at your thread. Is the vacuum port for the wiper plugged, hooked up to the wiper, or open?
     
  6. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    The 1 1/2 is NOT a setting, it is just an average set that is likely to get the thing started. In and out till it is happy, maybe a touch out then. On new setup you may have to adjust the idle speed screw to a happy RPM, then repeat the mix screws, perhaps more than once as each influences the other,
     
  7. Further to that, I screw each idle screw in one at a time until the engine starts to slow and lope, then back out slowly until it runs smooth and at fastest revs. Repeat with the other screw. This might have to be repeated a couple of times to get the balance nice.
     
  8. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member


    currently it is open. haven't figured out what it hooks too, so until then i leave it open :rolleyes:
     
  9. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Uuuuhhh...you now have a vac leak above the left throttle and another into left venturi...small but enough to significantly FUBAR carb functions.
    Plug that hole---it has no use on a stock 48, only with the vastly inferior '49 up distributor. (your distributor and wipers hook up right below carb on left side, and there is no use at all for that hole on middle of back of carb)
     
  10. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

    thanks bruce... i'm a nooby when it comes to carb-ed vehicles, so i can use all the help i can get. us youngsters only know fuel injection :) I'll give it a shot tomorrow.

    could that be why i can't get her restarted after i cut the engine?
     
  11. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Belay that...I see the writer above was referring to your stock vac hookup below carb. Different part, SAME PROBLEM...mixture is messed up! Sttel line needs to run to front cover where it meets its job, the straight out wiper connection must be hooked up or plugged for now! You are adjusting a carb that is probably leaking more air below the gas feeds than it is running past throttle at idle!
     
  12. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    To plug it, just use a bit of hose connected to the fitting with a screw in the end of the hose.

    Don't mess up that fitting. The are kind of hard to come by. Well at least I couldn't find one when I was looking. Someone probably has a bucket of them in their garage!!!

    Convenient place to hook a vacuum gauge to.
     
  13. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    One thing at I time I guess. But will it not restart after the engine is hot?
     
  14. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

    Correct. For example today, I tried to move it out of the garage and turn it around (so that the front of the car was facing the street). Upon attempting to do that (mind you i have about 5 minutes of actual driving time in this, so stalling still happens a lot >.< ), she stalled, and as usual, I was unable to get her started.

    So yes, I can not get her restarted after the engine is hot.

    I was attempting to set the idle and mixture screws like Bruce suggested, but had to get it out of the garage as there's a hole in the exhaust and it was getting quite stuffy in there as you can image.
     
  15. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

    i think my biggest problem here is that i don't know 100% for certain what she's supposed to sound like when properly tuned...
     
  16. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    First, did you plug the hole?

    Second, adjust the idle screws. Just get it running right now.

    The restart can be a few things. Fuel or electrical. 5 minutes isn't really enough time to get it hot to the point that the coil or condenser will malfunction. They tend to do suspect.
     
  17. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

    1) Yes, the hole is plugged.

    2) I get her running for about 10 minutes or so before i do anything. when i said 5 minutes, i meant 5 minutes of wheels moving with me behind the wheel. All i did was try to move her, stalled it, and then i am unable to get it restarted. I will try agian tonight, but after all the attempts of the past week the battery is dying... back on the charger for that :-/
     
  18. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Be suspicious of the coil. Aged coils run fine for a few minutes, then go into rapidly increasing misfire.
    Idle on a stocker should be slow and smooth, but for now a bit fast will help keepitrunning until you hunt down your troubles.

    Required reading: Service manual reprint, V-24 on book section of C7G Ford parts.
    Gettitnow without fail.
    If you want more, stuff to consider is the '39-48 service manual (actually a slightly padded reprint of a 1946 shop manual from Ford of Canada), the owner's manual, and the '28-48 parts book, then get all the service bulletins.
    The V-24 volume is just plain necessary right now.
     
  19. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

  20. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Yes, that's it. As with the Shop manual, it is a reprint with minor extra info of a 1946 publication.
    That one, followed by the pricier shop manual, would be my first two choices, though as a seriously disturbed fanatic I read only originals...
     
  21. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

    well this one happened to be in the glove compartment when i bought the car. lucky for me i guess as C&G wanted $60 for it!

    Well i'll-be-dipped! after closer inspection of the book, there is the part on carb tuning and adjustments...

    unfortunately i haven't been able to find anything on specs for the coil to tell whether or not i need a new one... would this be the reason i can't get it restarted once the engine is hot?
     
  22. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    Earlier post I meant. "Tend to be suspect".

    As Bruce said. Yes it can.

    If you have the time and a little money your best bet and bang for a stock dizzy, would be to send it gmcbubba here. Also get skip to rebuild your coil, I think gmcbubba does them too. Either way a good skip/gmc coil is a good thing. Order a couple condensors too.

    The crab dizzy is a good one and pretty easy to work on.
     
  23. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    On the coil, just have someone spin the engine with strter while you hold a secodary wire from coil to about 1/4 inch fron a cylinder head nut. You will need to pirate an extra wire since the far end of yours is buried with distributor cap...
    Test once with engine cold...you will likely see and hear a fat blue spark with a serious snap to it.
    Run car to point of trouble, repeat test. A dying coil will at this point be producing a thready looking yellow spark that is too feeble to light your fire.
    Condensor test...easy to remove, so remove it and put on a condenser from just about anything you have around...even if capacity differs a good condenser will do fine as a test piece.
    If it doesnt fit easily, the test one can be connected at coil primary terminal that leads to distributor, with its bracket grounded to coil bracket or by a jumper wire (two alligator clips on a piece of wire)
    If still no trouble found, use the jumper to bypass the ignition resistor. On '48 that should be atop the coil...on '46-early '47 it is inside car near wiring hole threough firewall.
    At that point things start to point to fuel delivery perhaps...
    First fuel test is simple...when car starts to decline, slowly pull out the choke. If fuel feed to engine is going away, choke will for a short time yank in more from the bowl.
     
  24. yblock292
    Joined: Oct 10, 2006
    Posts: 2,937

    yblock292
    Member

    on the hot start check your fuel pressure, 2 pds to 2 1/2 is all they need.
     
  25. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    I would at that point go a step further and bypass the entire fuel system abaft the carb...there are multiple possibilities, especially in a car that has been sitting a lot.
    I would run a hose from a Moon tank or lawnmower can to carb for gravity feed, runnit past the 5 minute mark, and see if that solved the trouble. Then if it did I would scrutinize the fuel deliver system piece by piece until I crawled back out at the filler cap...checking it for open vent as I went through!
     
  26. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    More stuff to do: Pull and inspect plugs. Clean and gap plugs to .025.
     
  27. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

    plugs are brand new and gapped. one of the first things i did since I couldn't get her started at all. thanks though!

    and thanks to Bruce and yblock for the suggestions also... going to be a busy night with the car and the MLB playoffs :D
     
  28. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Have your apprentices check the coil while you watch the MLB. You'll be able to assess coil performance by the quality of the screams at each spark.
     
    Chebby belair likes this.
  29. 48Tom
    Joined: Sep 19, 2011
    Posts: 46

    48Tom
    Member

    ok now that i'm done laughting, i can thank you for the words of wisdom and go grab some parts from my local parts shop...
     
  30. railroad
    Joined: Feb 3, 2010
    Posts: 242

    railroad
    Member

    I hope some of the advise cures the problem and it cranks, runs and re cranks good, BUT it sounds like it might be rich. You mentioned you rebuilt the carb. Did it come with a new power valve? It may be one of the newer styles that will not seal without some modifications to the carb and or the power valve. If none of the simple stuff turns up anything and the engine is sorta chugging, I know that term could mean a lot, I would look at the power valve. There are some articles and sites that sell a modified power valve for the 94s. I think they recommend a 7.5 for a single carb set up.
    good luck,
     

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