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75 CJ5 Timing

Discussion in 'Intermediate CJ-5/6/7/8' started by shibby12435, Feb 22, 2011.

  1. Feb 22, 2011
    shibby12435

    shibby12435 Member

    Columbus, MS
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    Apr 16, 2009
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    I've searched and searched but i've hit a wall on this one. Just rebuilt my 258 and have it all back together and running. I have a Weber Carb, No EGR, and the presolite distributor. I rotated my engine to TDC, making sure it was on the compression cycle and set the rotor to #1 position.

    The engine cranks up and runs. I put my timing light on it t and if I even get close to the factory setting (3-5 BTDC) the engine starts to idle like crap. I hooked up my vacuum gauge and my best reading is at what might be 20-30 BTDC (not even on the range of the indicator). The position the dizzy is in has the vacuum advance pointing right out the passenger side, 90 degree to the block.

    Im going to post pics soon, rebuilt the engine, trans (T-13A), and transfer case (dana 20). The body looks like crap right now but that's next on my list.

    EDIT: gonna try moving one full notch back, thinking im off a tooth
     
    Last edited: Feb 22, 2011
  2. Feb 22, 2011
    DREDnot

    DREDnot Not new to JEEPS

    AZ
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    646
    Is the timing chain and sprockets new?
    Could be slack/skipped if old and off a tooth if new.

    Is your harmonic balancer new or original?
    If original, it may have slipped on the rubber ring.(common) If it's new, it may be from a slightly different application with the notch to crank key relationship that is different.

    Like the difference between a 74 and earlier...

    [​IMG]

    and a 75 and later...

    [​IMG]
     
  3. Feb 22, 2011
    shibby12435

    shibby12435 Member

    Columbus, MS
    Joined:
    Apr 16, 2009
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    74
    New timing chain and sprockets. I was pretty sure I lined everything up right when I installed it. If the mechanical timing was off would it still idle smooth? When I twist the distributor it idles really nice but the timing marks are not even close. The balance is old, anyway to tell if the balance has slipped? When I put the timing mark on the 0 on the indicator the #1 Cylinder appears to be at TDC when looking in the spark plug hole.
     
  4. Feb 22, 2011
    DREDnot

    DREDnot Not new to JEEPS

    AZ
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    Which way the distributor points is technically irrelevant if the wires are where they need to be to run.

    That being said, I believe that the correct orientation of the vacuum advance is to be pointing generally toward the front of the engine. I put the rotor pointing toward the fuel pump for #1

    [​IMG]
     
  5. Feb 22, 2011
    shibby12435

    shibby12435 Member

    Columbus, MS
    Joined:
    Apr 16, 2009
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    74
    Here is what mine looks like:

    [​IMG]
    [​IMG]

    The Red line I drew is where the rotor is, #1 position, I THINK. I can make it run fine it just bugs me big time that the timing isnt even on the indicator.
     
  6. Feb 22, 2011
    shibby12435

    shibby12435 Member

    Columbus, MS
    Joined:
    Apr 16, 2009
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    Nice looking engine DREDnot, gives me something to go off when I get that point with mine.

    I am in the military and moving to my next duty station very soon and I need this jeep to run to help with moving it around. So right now Im just in a race to make it run right.
     
  7. Feb 22, 2011
    shibby12435

    shibby12435 Member

    Columbus, MS
    Joined:
    Apr 16, 2009
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    If my timing is ok, but say the mix was WAY off on the carb, could adjusting the timing that extreme make up for the bad mix? This is my first time working with a carb and im lost

    I also just put my vacuum test gun on the distributor and it doesnt hold any vacuum, time for a whole new distributor?
     
    Last edited: Feb 22, 2011
  8. Feb 23, 2011
    bigjohn

    bigjohn Member

    Kelso Wa
    Joined:
    Mar 18, 2010
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    868
    It looks like you may be a tooth off on your distributer gear. Take a look at the positioning on DREDnot's number one position, and then yours. Number one on mine faces more towards the front of the jeep. I would start by hand turning the engine to tdc according to your timing marks, rotate the distributer a tooth over, or counterclockwise, and reset your wires off of the new number one. If the distributer does not completely seat when reinstalling, use a long screw driver to turn the oil pump drive a bit until it does.
    Hope this helps bud.
     
  9. Feb 23, 2011
    shibby12435

    shibby12435 Member

    Columbus, MS
    Joined:
    Apr 16, 2009
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    Does your distributor look like mine? Since the vacuum advanced is screwed I need to make a decision on whether to replace this one ($55 at Advance Auto) or upgrade to HEI or something along those lines ($$$$) lol

    I will try going another tooth towards the front of the engine in the morning.

    Should have marked it when I took it off :oops:
     
  10. Feb 23, 2011
    bigjohn

    bigjohn Member

    Kelso Wa
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    Mar 18, 2010
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    868
    Haha, I know what you are going through. I just swapped to HEI last weekend, and spent quit a bit of time figuring out the distributer positioning and number one. Turns out, I had the firing order right, but on the wrong rotation. Haha, live and learn.
    As far as the HEI, I found a guy a few weeks ago on craigslist selling a dui hei unit with the $90 wires for $100. Those are pretty spendy units, but Ive heard the CRT hei's from 4wd.com work fine, as long as the drive gears are not hardened. My opinion though, one of the best mods to the engine yet.
     
  11. Feb 23, 2011
    DREDnot

    DREDnot Not new to JEEPS

    AZ
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    I just swapped in a later duraspark distributor out of a 77-79 cj (NAPA p/n 48-4691) and an ignition module (NAPA p/n TP40SB) to convert from my original Delco style point ignition. It is a drop in system that only requires some simple wiring to totally replace the universally crappy prestolite system that cannot be upgraded or modified.

    Before you spend any money to buy a rebuilt dist., give a thought to upgrading to the later duraspark system.

    [​IMG]

    [​IMG]
     
  12. Feb 23, 2011
    DREDnot

    DREDnot Not new to JEEPS

    AZ
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    When you did the timing chain, did you align the timing marks per the factory service manual? THEN did you do the test (per the manual) to verify cam timing.

    If you verified the 15 pin count, then you won't need to remove the timing cover to double check. My feeling is that you slipped the pulley or have a 74 or older pulley that is giving you a false reading on the timing. Time it to the best vacuum and it runs smoothest. If it drives fine, you shouldn't have to fret about where the timing mark sits.
     
  13. Feb 23, 2011
    shibby12435

    shibby12435 Member

    Columbus, MS
    Joined:
    Apr 16, 2009
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    I aligned the marks, but did not rotate it and then count the pins. Im going to pull the timing cover off and check.

    The 75 is the first year after the points system, I think its called BIS or something like that. My vaccum advance unit doesnt hold any vacuum so Im assuming this means it's screwed. I checked out the Napa part numbers, is that a better unit than the current one I have?
     
  14. Feb 23, 2011
    BLACKMGTD

    BLACKMGTD STEVE

    CANTON CT
    Joined:
    Aug 19, 2006
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    110
    i THINK IF YOU REPLACED THE VAC ADVANCE, YOUR PROBLEM WILL BE SOLVED. I have had to replace the VA in my '75 a few times,,,,
     
  15. Feb 23, 2011
    DREDnot

    DREDnot Not new to JEEPS

    AZ
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    I spent a lot of time researching ignition upgrades that are commonly available for this vintage powertrain.

    Stuff like Drop-in pointless conversions for the delco dist. that would be kind of a retro-style upgrade common back then.

    I started gathering parts to convert to HEI with a junkyard dist. out of a chevy six. Almost bought all the new parts to rebuild and install.

    Then I decided to just go with a well liked and common-parted sytem that is drop-in to the 258 as it was the system used in the '77-'79s.

    Just google search around JEEP DURASPARK IGNITION and do some reading.

    This is the first thing that I have seen with all this fantastic, glowing reports of "100% improvement!!!" or some such B.S. that has actually come through and made a substantial difference in how the motor starts, runs, and idles.
    It eliminated drivability problem that I was sure were carb related.
    AND it passed AZ emissions!

    I think I may have $125 in it.
     
  16. Feb 23, 2011
    DREDnot

    DREDnot Not new to JEEPS

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    From what I've read, universal opinion seems to lean toward being that any money spent on the prestolite unit (with the double plastic vac. adv.) is folly.

    I know that the few bucks I spent on freshening up my Delco point dist. was regrettable.
     
  17. Feb 23, 2011
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Medford Mass USA
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    Absolutely. Get rid of the Prestolite stuff. Notoriously unreliable, expensive to repair, low availability, and a dead-end detector technology.

    There are a lot of cars out there still with Delco points distributors. Parts are easy to source, they are quite reliable (for a points distributor), and there are even hop-up parts available.

    However, the Duraspark (or even GM HEI) conversion is so easy and cheap, I would go that way rather than buy hot-rod parts for the Delco. The main durability issue (points) will be gona, and you'll be compatible with a much wider world of aftermarket options.

    "BIS" is breakerless ignition system. It's a generic term. You have the Prestolite system - the white plastic vacuum canister on the side of the distributor is distinctive (Another reason to get rid of the Prestolite distributor).
     
    Last edited: Feb 23, 2011
  18. Feb 23, 2011
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Medford Mass USA
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    My '75 had the Prestolite stuff. It now has the TFI'd Duraspark distributor with a HEI module.

    [​IMG]

    This is a 304, but the same process applies to the 232 or 258, with different parts.
     
  19. Feb 23, 2011
    shibby12435

    shibby12435 Member

    Columbus, MS
    Joined:
    Apr 16, 2009
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    Found this pic of when I pulled the motor, the distributor needs to be rotated one tooth counter-clockwise. I have been reading about the duraspark conversion and looks like I can source most things from either local parts store. Any opinions on brand to use?

    [​IMG]
     
  20. Feb 23, 2011
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Medford Mass USA
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    I think most parts stores offer the A-1 Cardone brand for remanufactured distributors.

    For the ignition parts, I like Standard Blue Streak, but anything with brass terminals should be ok. Supposedly the non-black plastics are a better dielectric than black plastic. I used the Summit custom wires.

    There's a good thread on the 258 TFI upgrade here, complete with detailed part numbers. http://www.jeepforum.com/forum/f8/i-6-teamrush-upgrade-definitive-669495/
     
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