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distributor doesn't quite fit

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by bdkmiller, Oct 10, 2002.

  1. bdkmiller

    bdkmiller Registered Member

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    distributor doesn\'t quite fit

    I am trying to set the timing on my '72 K5 but the vacuum advance dashpot is hitting the tranny dipstick. The timing is close but it still pings on hard acceleration. I could try & relocate the dipstick, but I would rather find an easier option. Can I switch the spark plug wires, ie. move each one place to the left & then reset the timing? Or would this create a problem?
    Thanks in advance,
    Brian
     
  2. chevyracing

    chevyracing 1/2 ton status

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    Re: distributor doesn\'t quite fit

    You can move the wires, won't hurt a thing. Sounds like the dist. is one tooth off, but moving the wires is a viable alternative to pulling the dist.

    John
     
  3. bdkmiller

    bdkmiller Registered Member

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    Re: distributor doesn\'t quite fit

    John, thanks for the quick reply. The distributor could very well be 1 tooth off. It is HEI, installed by the previous owner.
    I'll give it a shot this weekend.
    Thanks,
    Brian
     
  4. chevyracing

    chevyracing 1/2 ton status

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    Re: distributor doesn\'t quite fit

    Brian,
    Another thing to consider why the timing is off so much would be the timing chain may have jumped. Not sure what you have for mileage, but if you still have an issue with getting it timed right and not running corectly when it is timed right you may want to take a peek and see.

    John
     
  5. bdkmiller

    bdkmiller Registered Member

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    Re: distributor doesn\'t quite fit

    ooohhh.

    Is there an easy way to check the timing chain, or do I have to remove the whole front of the engine? I bought the blazer from a guy this summer, partially restored. I finally got it up to daily driver status, but it still needs some tweaking. He had replaced the distributor with a HEI unit but since he wasn't driving it, he didn't set the timing.
    Thanks,
    Brian
     
  6. chevyracing

    chevyracing 1/2 ton status

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    Re: distributor doesn\'t quite fit

    I would try to time it first. If it times out okay I wouldn't sweat too much. The best way to check the timing chain is to look at it. The other way is to check the back lash between the crank and cam. You have to pull a valve cover to do that. Basically you will want to see how much you can move the crank back and forth without and pushrods moving. Someone else will have to give you the allowable limits on that, I don't know them, but I believe there should be almost none. I run gear drive in mine so there is virtually zero back lash in mine.

    John
     
  7. Roostr84

    Roostr84 1/2 ton status

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    Re: distributor doesn\'t quite fit

    I would make sure the guy got rid of the resistor wire too when he switched over to the HEI, since you're in there already.
     
  8. jeffro

    jeffro 1/2 ton status

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    Re: distributor doesn\'t quite fit

    Another way to check timing chain slop is looking at the distributor rotor while turning the crank back ond forth.
     
  9. chulisohombre

    chulisohombre 1/2 ton status

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    Re: distributor doesn\'t quite fit

    no problem with moving the wires.just have to do it one at a time so yoiu dont get them mixed up.definitely check to see if the wire was replaced with a regular wire and doesnt still have resister wire to the distributor.i had mine go out on the way to work because i didnt know that it would cause a problem.i strait wired mine to the fuse panel ignition spot and have had no problems.
     
  10. Robin

    Robin 1/2 ton status

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    Re: distributor doesn\'t quite fit

    If the truck is running fine, don't assume the timing chain has jumped a cog, you can drop the HEI in so that the vacuum port is pointing anywhere.

    Just make sure that:
    1) the timing pointer is pointed to 0 deg.
    2) the #1 cylinder is at the top of the compression stroke
    3) the rotor is pointed to the #1 wire

    You can check for 2) by pulling the #1 plug and sticking your finger in the hole. Turn it over until you get what feels like 150 lbs of air pressure pushing your thumb off the hole. At the point where there is no pressure (TDC), you have #1 ready to fire.

    There are tools that make this more scientific, but the timing pointer should roughly be pointing @ 0. From there, start it up and dial-in the timing.
     
  11. bdkmiller

    bdkmiller Registered Member

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    Re: distributor doesn\'t quite fit

    Thanks guys
    On further examination, it looks like my distributor is off by a tooth or so. I moved the plug wires & now the vacuum port hits the intake manifold. But the timing is a little better. So this weekend, I am going to pull the distributor & see what I can do. Unfortunately, the previous owner pulled this engine from some other vehicle & it has no timing marks. I grabbed the timing marks sheet metal part from a junkyard engine, but I can't put it on my engine due to the power steering pump. So I use the "change the timing & drive it" technique.
    But I am close now, it only pings under pretty hard acceleration now. Plus it is a little bit quieter.
    Thanks again,
    Brian
     
  12. Robin

    Robin 1/2 ton status

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    Re: distributor doesn\'t quite fit

    For future reference you should probably set TDC. Eastwood has a whistle that screws into the #1 hole.

    http://www.eastwoodco.com/
    Top Dead Center Indicator With Extension

    Item No. - 46048
    Find TDC (top dead center) with the "whistle" quickly, easily, and precisely every time! As the piston rises in the cylinder, compressed air escapes through the whistle. When the Whistle stops, the piston is at TDC. It's that simple! Dual thread pattern (14mm and 18mm) with attached 22" hose fits most engines. Attached extension reaches into tight access areas.

    Regular Price: $21.99
     

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