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14+* of timing just to run?

Discussion in 'The Garage' started by gimmie11s, Sep 3, 2005.

  1. gimmie11s

    gimmie11s Registered Member

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    need some help diagnosing a problem with my 84 K5. It needs the base timing to be advanced so much that it doesnt even register when i time it just to run. If i set it at the factory specified 6* BTC, it simply won't run.

    Also, it runs so rich that it spits out black smoke whenever its revved up.

    what are common places to check for vacuum leaks?

    Compression is within 8 psi. of each other all the way accross with the lowest being 148 psi.

    would removing the intake mani and resestting it be a good idea in an attempt to get rid of possible vacuum leaks?

    thanks-
     
  2. Guss

    Guss Registered Member

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    they make a vacume pump to see if it leaks. you can pump it and watch the guage tou see if it leaks
     
  3. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Are you SURE that the dizzy is installed correctly?


    Being off by one tooth on the drive gear could be the culprit to those crazy-looking timing numbers.... :thinking:
     
  4. Mad-Dog

    Mad-Dog 1/2 ton status

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    Even if the dist gear was off a tooth then the dist would have to be rotated in direction or the other to compensate,
    not disconnecting the vacuum advance and/or weak springs in the mechanical advance mechanism could cause the erroneous readings when a using a light to set the base timing.
    Using a plug wire other than #1 would also cause false readings but let's hope that's not the case..... :crazy:

    Using the manifold vacuum instead of ported vacuum will also cause problems with the light.

    Hope this helps.... :bow:
     
  5. HarryH3

    HarryH3 1 ton status Author

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    How many miles are on the rig? If it's 100K+, then it's possible that the timing chain jumped a tooth so that the cam and crank are no longer exactly in phase.
     
  6. gimmie11s

    gimmie11s Registered Member

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    hmmm... ive reset the dist several times in hopes that it was off. IT seems to ONLY run the way i have it set now. bring up the motor on compression in the number 1 cyl is how i achieved TDC for setting the dist.

    It runs an HEI dist with no vacuum advance and nothing mechanical inside the dist that i can see.

    buying a new dist was another option.... would that be a waste of money?
     
  7. gimmie11s

    gimmie11s Registered Member

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    she's got about 160k on her but the previous owner installed a GM Goodwrench longblock recently.
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    Are you saying you've got a dist. that has two electrical connections on the side??

    No mech or vac advance means it's computer controlled, and that means NO advance if its not hooked up.

    An '84 is likely not going to have CCC stock, but even if it had ESC, it still would have advance.
     
  9. gimmie11s

    gimmie11s Registered Member

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    YES SIR.... exactly.

    it has the 3 wire connector just underneath the coil and another connector (red wire) right next to the three wire connector.

    it does in fact act like the timing is not advancing. what needs to be done to make sure it is??
     
  10. Mad-Dog

    Mad-Dog 1/2 ton status

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    Okay.....so it's got HEI with EST or electronic spark timing, you must disconnect the EST wire from the dist when setting the timing.
    If you're having trouble tuning the engine correctly something else is causing trouble such as the module itself which should be a 4 or 5 pin unit.
    It really makes no difference what position the dist is dropped in the motor as roating the wires on the cap to a position where the firing order is correct and the dist is in a comfortable position which is usually where the factory installed it to begin with, usually if the dist is too far out of phase the plug wires will not reach to their respective terminals. :bow:
     
  11. gimmie11s

    gimmie11s Registered Member

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    i may have narrowed it down to a few tight valves. im guessing that the valves have NEVER been adjusted in this motor since it was put in probably 40k ago.

    this should explain the extremely rich condition shouldnt it? being that the valve/s never close all the way so complete combustion is not taking place and raw fuel is simply passing through the chamber and out the exhaust.... :confused:

    ill adjust all vavles and report back how it turned out.

    -d
     
  12. HarryH3

    HarryH3 1 ton status Author

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    That doesn't jive with this from your first post:
    You can't have good compression if the valves don't close all the way. :rolleyes:
     
  13. Mad-Dog

    Mad-Dog 1/2 ton status

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    Valve lash is not likely to decrease with use or lack of adjustment, excessive lash would be a more likely scenario.

    Maybe you should elaborate on what type of fuel system the engine has as I am terrible at guessing or reading minds, not everybody is fortunate enough to have a '83 sitting out in front yard to open the hood and say....oh, that's what he's got :bow:
     
  14. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Without having a vacuum advance or mechanical advance you have a computer controlled ignition timing. You should find a brown wire with a white stripe somewhere near the brake booster that you MUST disconnect first before trying to time the engine.
     
  15. gimmie11s

    gimmie11s Registered Member

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    good point. i didnt think of that. ill be adjusting in the morning anyway for peace of minds sake.
     
  16. gimmie11s

    gimmie11s Registered Member

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    haven't done this yet. ill give it a shot.

    thanks-
     
  17. gimmie11s

    gimmie11s Registered Member

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    today i adjusted valves, installe new ignition coil, new EGR valve, and got most of the factory vacuum lines going to the places they belong. Its running MUCH better but still very rich.... it still makes me tear up if i stand around for just a few seconds while idling.

    anyone have the factory vacuum diagram for a 1984 chevy 350? my sticker is faded and torn in some places and i still need to intall about 4 more vacuum lines....

    thanks

    -d
     

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