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  1. #21
    Join Date
    Sep 2004
    Location
    Orlando, FL
    Posts
    950
    Country Flag: United States
    Start with all four idle/air screws 1 turn out... set your idle to 1000rpms. Verify TDC... did I mention "verify TDC"? I know you put the timing tap on their but it doesn't take long to verify TDC.

    How much mechanical/vacuum advance do you have in the distributor? If's it's 12-14* set your initial timing to 18* for 30-32* total... you can verify total by holding the rpms at 3000rpm and checking your timing. It should be "all in" by then.

    You'll need to know how much advance you have it you want it to run well down the road... you may have to start by verifying total timing... then check your initial so you know what your mechanical/vacuum advance is.

    What type of distributor do you have btw?

    Back to the carb:

    Adjust your idle screws... check the vacuum gauge... adjust the idle back to 1000rpms... adjust idle screws... check the vacuum gauge... adjust the idle back to 1000rpms... repeat as necessary.

    Shoot for an AFR of 13.2 in park should get you to 14.0 when driving.
    SMSgt Ty Ingle, USAF
    "CF71" - Freedom Bird
    Hoodpins.com, Inland Empire Driveline, Billet Accessories Direct, Modo Innovations, AutoRad Radiators, Morris Classic Concepts, Marquez Design, Anvil Auto, Fesler Billet, US Collision (DOOM), AGR Performance, Pro-touringF-body.com, Phoenix Transmission Products, Shiftworks, ACC Carpet, Hedman Hedders, BMR Fabrication, American Autowire, MityMounts, TIN INDIAN Performance, Kauffman Racing Equipment, Pypes, RobbMc Performance, WMC, Holley, NOS, PST

  2. #22
    Join Date
    Dec 2006
    Location
    California
    Posts
    1,348
    Country Flag: United States
    What's an easy way to verify tdc without a piston stop? I guess I could pull the belts and crank pulley and put the degree wheel back on and use my dial indicator on a valve.

    It's just that I did all that when we installed the cam so I don't really want to do it again. If there's an easier way, I can do it.

    Initial timing was only 9. With vacuum advance connected to full manifold vacuum, it went up to 19 at idle. So my distributor only gives 10 with vacuum.

    Distributor is an MSD pro billet.

    I bumped the timing up to 16 initial, I forget what the total was at 3000. I knew I should have written it down.

    I have an adjustable vacuum canister, I just didn't want to install it right now because I'm already having such a hard time getting the carb dialed in. I didn't want to add more stuff to mess with.

    So far at 900 rpms I have 13" of vacuum.

    I'm pretty sure the O2 sensor is useless at this point. I took it for a few test drives and the first two with the low initial timing, it just showed 9.0. After bumping up the timing, it maxed out at 10.7.

    We pulled a plug and it looked almost perfect. The threads were black but the porcelain was a dark tan color. Darker than ideal, but nowhere near as bad as the old plugs.

    I'm probably going to get a new O2 sensor just to rule that out.
    Matt

    69 Nova - 357, TKO600, Tru Turn, some other stuff, awaiting LS1 swap
    71 Duster - all stock, slant 6, automatic. awaiting HEMI/T56 swap

  3. #23
    Join Date
    Dec 2005
    Location
    San Leandro, CA
    Posts
    920
    Country Flag: United States
    You set initial with vacuum disconnected and plugged. Mechanical advance also with vacuum disconnected and is checked at 3000 rpm. The mechanical advance is controlled by weights and bushings in the distributor. When it’s “all in” is controlled by the springs in the distributor.

    Measure initial and total timing then report back.
    Steve
    '68 Camaro - SBC, TKO600, 3.73 Moser 12-bolt, Speedtech, AFX, Hotchkis, Forgeline, Ron Davis and C5 brakes with Kore3 park brake kit. Soon to be EFI with Holley Terminator.
    Check it Out Here

  4. #24
    Join Date
    Sep 2004
    Location
    Orlando, FL
    Posts
    950
    Country Flag: United States
    TDC = pull the #1 spark plug and put a rubber cork in the hole... rotate the engine under the cork shoots across the garage! LOL

    Also check to make sure the rotor in your distributor is pointing directly at the #1 spark plug wire/terminal in the distributor cap.

    You HAVE TO make sure your timing is right or you're just chasing your tail... Watch these videos if you haven't already:

    https://www.youtube.com/watch?v=FHX1yXVyIMg = Finding TDC with your thumb over the hole

    https://www.youtube.com/watch?v=UYGU7mTwsZc = Setting timing and total timing to 35*

    I'd run the light blue/light silver spring combination with the black bushing in the MSD Pro Billet distributor.

    It'll bring total timing "all in" by 3000rpm and then set your total time to around 35*. HTH
    SMSgt Ty Ingle, USAF
    "CF71" - Freedom Bird
    Hoodpins.com, Inland Empire Driveline, Billet Accessories Direct, Modo Innovations, AutoRad Radiators, Morris Classic Concepts, Marquez Design, Anvil Auto, Fesler Billet, US Collision (DOOM), AGR Performance, Pro-touringF-body.com, Phoenix Transmission Products, Shiftworks, ACC Carpet, Hedman Hedders, BMR Fabrication, American Autowire, MityMounts, TIN INDIAN Performance, Kauffman Racing Equipment, Pypes, RobbMc Performance, WMC, Holley, NOS, PST

  5. #25
    Join Date
    Dec 2006
    Location
    California
    Posts
    1,348
    Country Flag: United States
    Yeah we checked total but I forgot what it was. I thought I'd remember but I didn't. I'll have to check again.

    I thought putting your finger on the spark plug hole was just a rough estimate?

    I thought you guys wanted me to like get a degree wheel and go clockwise/counterclockwise to make sure the balancer's zero mark was actually TDC.

    I coulda done the finger thing if I knew that's what you were talking about, lol.

    I'll see if I can make time to do some tinkering tomorrow and check timing again.
    Matt

    69 Nova - 357, TKO600, Tru Turn, some other stuff, awaiting LS1 swap
    71 Duster - all stock, slant 6, automatic. awaiting HEMI/T56 swap

  6. #26
    Join Date
    Dec 2005
    Location
    San Leandro, CA
    Posts
    920
    Country Flag: United States
    Check it with the vacuum advance disconnected and plugged.
    Steve
    '68 Camaro - SBC, TKO600, 3.73 Moser 12-bolt, Speedtech, AFX, Hotchkis, Forgeline, Ron Davis and C5 brakes with Kore3 park brake kit. Soon to be EFI with Holley Terminator.
    Check it Out Here

  7. #27
    Join Date
    Dec 2006
    Location
    California
    Posts
    1,348
    Country Flag: United States
    Been a while, but I finally got a chance to take the car to work so I got a good 25 Mile drive to see how it's running.

    At idle and cruising on the freeway when it's flat, it's running at 13.7-14.0:1.

    But if I try to give it a little more throttle, like say 50%, or there's an incline, it goes up. Getting on the freeway it hit mid 15's and peaked at 16:1, and then further on the freeway when I hit an incline it peaked at 18:1!

    Since the idle is almost perfect, I'm going to assume it's a secondary issue.

    I don't remember what secondary jets are in it, but I'm going to bump them up a decent amount. I'd rather make a bigger change and just have it run richer but still be able to accelerate than still be lean and risk damaging anything.

    Right now I can't even accelerate hard because it's so lean that the engine just sputters and runs like crap.
    Matt

    69 Nova - 357, TKO600, Tru Turn, some other stuff, awaiting LS1 swap
    71 Duster - all stock, slant 6, automatic. awaiting HEMI/T56 swap

  8. #28
    Join Date
    Mar 2014
    Location
    Yuma, AZ
    Posts
    604
    Country Flag: United States
    Yes, go with a couple sizes bigger on the secondaries. Mine ran about 14:1 cruising, 14.5:1-15:1 if I tried to accelerate, and at WOT would spike up to about 16:1. I went a size or two bigger on the secondary jets. Find a carb guy to pick the jets for you. I went into a speed shop and the guy helped me out, the jets I thought I needed were completely wrong because of how Holley jets are labeled apparently.
    Nelson
    1969 Chevelle "Cone Smasher" Family Project
    https://www.pro-touring.com/threads/...uot?highlight=

    1984 "Rustang" GT, 5.0, 5 Speed Project
    https://www.pro-touring.com/threads/...T-(Slow-Build)

  9. #29
    Join Date
    Dec 2010
    Location
    Northern Virginia
    Posts
    3,020
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    I got so tired of messing with Holley carb tuning. You really need to take a serious look at an EFI system like FiTech. These EFI systems have come down in price to the point that anyone can afford to make the switch these days. Everyone who makes the switch to EFI says they wish they had done it sooner.
    Steve Hayes
    "Dust Off"
    68 Camaro

    Speed has never killed anyone. Suddenly becoming stationary, that's what gets you!
    "Jeremy Clarkson"

  10. #30
    Join Date
    Aug 2005
    Location
    Hamilton, NJ
    Posts
    4,211
    Country Flag: Swaziland
    Quote Originally Posted by DarkoNova View Post
    Been a while, but I finally got a chance to take the car to work so I got a good 25 Mile drive to see how it's running.

    At idle and cruising on the freeway when it's flat, it's running at 13.7-14.0:1.

    But if I try to give it a little more throttle, like say 50%, or there's an incline, it goes up. Getting on the freeway it hit mid 15's and peaked at 16:1, and then further on the freeway when I hit an incline it peaked at 18:1!

    Since the idle is almost perfect, I'm going to assume it's a secondary issue.

    I don't remember what secondary jets are in it, but I'm going to bump them up a decent amount. I'd rather make a bigger change and just have it run richer but still be able to accelerate than still be lean and risk damaging anything.

    Right now I can't even accelerate hard because it's so lean that the engine just sputters and runs like crap.
    I would be looking at squirters, accelerator pump cam, and if its a vacuum secondary the spring before i messed with jets.
    Scott from NJ.

    Vent Windows Forever! ... My junk, featuring the Red Dragon ... NastyZ28 ... NJ Camaros & Firebirds

    Feather-light suspension, Konis just couldn't hold
    I'm so glad I took a look inside your showroom doors

  11. #31
    Join Date
    Dec 2006
    Location
    California
    Posts
    1,348
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    I went back to the stock 82 secondaries, didn't make a bit of difference.

    I tried messing with the secondary opening rate, QuickFuel uses a screw instead of springs for the vacuum secondaries. I forget which way we tried turning it but it didn't help.

    We watched an episode of Roadkill Garage where they were tuning a carb with a wideband and they said the power valve is supposed to help with part throttle transitioning/load.

    So I bought a new power valve with a higher number. If I'm understanding it right, the higher number will open sooner, so it should help richen it up when I need it to.

    I'm going to install it today after work so we'll see.
    Matt

    69 Nova - 357, TKO600, Tru Turn, some other stuff, awaiting LS1 swap
    71 Duster - all stock, slant 6, automatic. awaiting HEMI/T56 swap

  12. #32
    Join Date
    Sep 2004
    Posts
    19
    Take your highest vacuum reading and divide by two. This is generally what size power valve you should run. Before you go crazy playing around with everything, write down your settings and the changes you made so if they don't work you can go back to the way it was.

  13. #33
    Join Date
    Dec 2006
    Location
    California
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    1,348
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    The bigger power valve didn't really do anything either.

    Not sure what else to do.

    It's weird because if I punch it, it goes super lean at around 2400rpm and sputters and falls on it's face. But if I keep the pedal to the floor, it will eventually work through it.



    But it honestly feels like a spark issue when it happens. That doesn't make sense, though, because if any plugs weren't firing, it should read richer when it happens.

    I don't know. I haven't had time to work on it since my last post since I'm working 12 hour days and 6-7 days a week. I'm almost at the point of just taking it to a shop, but the shop I used to use doesn't tune carbs anymore. They only work on carbs if it's a smog era vehicle and it came from the factory with a carburetor.
    Matt

    69 Nova - 357, TKO600, Tru Turn, some other stuff, awaiting LS1 swap
    71 Duster - all stock, slant 6, automatic. awaiting HEMI/T56 swap


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