timing question

[83bowtyblazer]

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

 

[POWERMAD]

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>

 

[tRustyK5]

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>

 

[HispanicPanic]

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>

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[tRustyK5]

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>

 

[dyeager535]

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>
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