Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

timing question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 83bowtyblazer, Aug 28, 2001.

  1. 83bowtyblazer

    83bowtyblazer 1/2 ton status

    Joined:
    Jul 29, 2001
    Posts:
    132
    Likes Received:
    0
    Location:
    Ft. Dix, NJ
    I have an 83 blazer with an 86 305 in it and when I nail it when it's cold, it knocks. I had a friend check the timing on it. It is set at...no joke here...+28 degrees. The sticker says it should be at 4 so we dropped it down to 4 and it had verry little throttle response. So we brought it back up to 26-28 range and it runs fine but still knocks when cold under a load. Is there a chance that the distributor was installed 1 tooth off?? Any help will be greatly appreciated. Ryan
     
  2. POWERMAD

    POWERMAD 1/2 ton status

    Joined:
    Mar 4, 2001
    Posts:
    3,466
    Likes Received:
    0
    Location:
    Oregon
    When I bought my K5 it had the same problem.
    I checked the timing and it was like yours 28*.
    I pulled the cap and found that the advance was stuck and was not working. the previous owner just crancked up the timing and called it good.
    After I got the advance to work and installed a recurve kit it runs like a champ.


    <font color=green> Too bad ignorance isn't painful </font color=green>
     
  3. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,178
    Likes Received:
    1,387
    Location:
    E-town baby!
    What Ron said...plus the timing chain has prolly stretched a bit. A friends Grand prix used to run best with about 8 degrees more advance than the specs called for. His chain was just worn a bit.

    Rene

    <font color=green>Dyslexics of the world...UNTIE!</font color=green>
     
  4. HispanicPanic

    HispanicPanic 1/2 ton status

    Joined:
    Mar 21, 2001
    Posts:
    351
    Likes Received:
    0
    Location:
    El Paso, Texas
    im running my jimmy at about 10-12 degress and it runs perfect now the one thing that has me confused it when i hook up my advance to the carb where its supposed to go (vacuum when accl.) it feels a little sluggash so i hook it up to where thers always vacuum I know its not right but hey it runs great like that for me i get better response and good highway and no pinging

    <font color=purple>I put the Panic in Hispanic</font color=purple>[​IMG]
    <a target="_blank" href=http://4x4.alloffroad.com>4x4.alloffroad.com</a>
     
  5. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,178
    Likes Received:
    1,387
    Location:
    E-town baby!
    You're still hooked up to manifold vacuum...just not at the carb. The vacuum signal will be exactly the same. The port on the carb may not have been the right one.

    Rene

    <font color=green>Dyslexics of the world...UNTIE!</font color=green>
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    If you set the idle with vac advance hooked up to "timed" vacuum (SOME of the Q-jets ports) then move to constant manifold vacuum, you are increasing the idle speed. You'll notice just about any vehicle takes off "stronger" when the idle speed is cranked up.

    Some GM vehicles hooked vac advance up to timed ports, some to constant manifold vacuum. Ive never seen one of our trucks hooked up to constant manifold vacuum (stock)

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</a>
    No anti-theft measures on your truck? No pity when its stolen
     

Share This Page