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My distributor STILL isnt working right!!!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Sparky, Aug 28, 2002.

  1. Sparky

    Sparky 1/2 ton status

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    I posted about a problem with my distributor a while ago, but i still have problems. I took the distributor out found out why the timeing was moving around and fixed it. The plate that the roter mounts to had rattled loose over the years and was pivotiing a few degrees here and there where it wasnt supposed to be. So I fixed that problem, but now I have a new one. I cant seem to find a way to get my mechanical advance to advance all the way. It will advance the timing from 10 degrees to about 20 or 25 degrees when it should be advanceing it to 30 or 35 degrees. I have tried every combination of springs under the sun and it still dosent advance past 25 degrees. I even drilled out the holes on the old weights and put in some bushings with no difference. I am starting to think about buying a new distributor if I cant figure it out. I cant think of anything else that would cause the problem besides the weights and or springs. Everything seems to be workign just fine when I operate it by hand. I dont know what else to try so i decided to see if any of you had any bright ideas. Lets hear what they are.

    Thanks
    Sparky
     
  2. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    HEIs only come with 20 degrees mechanical advance....
     
  3. Sparky

    Sparky 1/2 ton status

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    Yeah, I know. My distributors mechanical advance is only advancing it by about 10 degrees. So with the initial timeing set at ten degrees and with ten degrees of advance i am only getting a total of about 20 degrees advance. It should be about 32 to 36 BTDC depending on what i set the initial timeing at.

    BTW... Which way is the center plate supposed to be installed. With the stamped part number facing up or down.

    Thanks again

    Sparky
     
  4. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    The numbers should be up on your center plate. Question being what springs are you using. Those fat springs from the smog era will make for one s l o w curve. Usually one fat spring and one medium spring (stock springs) will make a curve that pulls off-idle all the way until 3,000. You will need to lessen your vac advance if you want to run into the 32-36 initial range. A homemade lockut out plate or buying an adjustable unit will be required. You can set your initial timing anywhere from 12-16 to get you into the 32-36 range. Then you'd need 8-12 degrees vac advance and you could even get up to 16 if you have EGR. Worry about the mechanical advance first and then just keep adding more vac advance until things fall off. I usual hook up to the port on the Q-Jet that doesn't have vac present at idle. You've spent some time setting up a good mechanical advance, the last thing you want is a piece thats meant for economy (vac advance) causing a bog off-idle.
     
  5. Sparky

    Sparky 1/2 ton status

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    Cool, thats what I thought on the center plate, but this article said otherwise http://www.dorianyeager.com/distcurve.html
    It tells you to mount it with the number on the center plate down.

    I have tried every combination of springs I can come up with. It still cant get it to advance more than 10 degrees no matter what i do. I guess I'll go try some more combinations and see what happens.

    Sparky
     
  6. Blazer_Boy

    Blazer_Boy 1/2 ton status

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  7. dyeager535

    dyeager535 1 ton status Premium Member

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    I'm wondering if different divisions did it differently. (notice, thats a Poncho page) Olds had different weight setup than Chev's (some years) so variations do exist.
     
  8. sosamantx

    sosamantx 1/2 ton status

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    fyi, some olds spin the opposite direction of a chevy. so, looking at the distributor, some of them spin (not sure if all of them) counter clockwise.
     
  9. Sparky

    Sparky 1/2 ton status

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    I was figureing that there was some difference in some of the Pontiac HEIs, and that is why they were saying to put the center plate on with the numbers face down. The "recurve" kit that I have (I'm just using the springs) says to put the weights on upside down for reverse rotation distributors so I am sure thats the case with that article.

    Anyways, back to my problem. I have tried every combination of springs under the sun so I have come to the conclusion that the maximum amount of advance my distributor will allow is the 15 degrees. I think its because of the center plate I have. It must be a california distributor or something. I think the number on the center plate is 409. And the weights are 139. Anyone know what maximum advance this combination will allow? Everything I read says that a stock HEI should provide 20 degrees of advance (+/- 1 degree), but mine will only get 15 no matter what I do.

    Maybe I will go grab a bunch of different center plates from the junkyard next time i get a cance.
     
  10. sosamantx

    sosamantx 1/2 ton status

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    try posting your questions here, this is a dealer website, maybe someone will know?? my bet would be that it is an emissions distributor?, and something is not letting it advance that much?? anyway, hope this helps.

    http://www.sallee-chevrolet.com/Discus/board.html
     
  11. Jay73K20

    Jay73K20 Registered Member

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    Why don't you use the weights and center plate that come in the recurve kit, wouldn't that be an excellent idea.
     
  12. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    Recurve weights never do a good job. Don't have any scientific explaniation why. I used the Mr. Gasket and Accel kits and they only wanted to give 15. It took a healthy amount of throttle and 3,500 rpm to get the advance all the way in. That was with the lightest springs too. Back to stock setup with one spring out of an old points distributor. Smooth right off idle to 3,000 rpm.
     

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