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More Timing Questions

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Hossbaby50, Feb 16, 2003.

  1. Hossbaby50

    Hossbaby50 3/4 ton status

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    Ok, I just went out and fired my truck up, and was messing with the timing to try and get it to run right. If you havn't seen my other posts, I can't get this thing to run right after I installed a new fuel pump about 2 weeks ago (and again a week ago).

    At first I thought it was the carb, but I have been messing with the timing and it runs fine if you are running ALOT of timing.

    Spec: HEI distributor with MSD 6 Offroad box, MSD Blaster SS coil, MSD cap & rotor, MSD HEI dust cover, MSD 8.5mm Super Conductor wires. All this on a 350 SBC.

    Problem: I was just messing with it, and to get it to run decent (not stumble terribly off idle) I have to advance the timing alot. I am running 30* BTDC at 650-700 RPM. This is with the vacuum tube running to the vacuum advance disconnected and pluged with my finger. As I can tell when I start to rev the motor up the timing runs to over 50*BTDC. Can someone tell me WTF here? I am going to pull the cap & rotor Tuesday to see if something is a miss under there. I drove it around with the above specs and it didn't ping from what I can tell. I was climbing a gradual hill in 2nd gear at around 3000-3500RPM and I could hear or feel any pings or knocks.

    I was thinking about the fact that the MSD multisparks, and I was wondering if the multispark would possibly give me a wrong reading (firing earlier then normal HEI) and therefore make it look like it is running more timing then it really is?
     
  2. Hossbaby50

    Hossbaby50 3/4 ton status

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    Well I just found this on the MSD website. Apparently I should have bought the crappy timing light with no adjustable knob.

    Timing Fluctuations
    If your timing seems to be jumping all over the place, check the following items:

    "What kind of timing light are you using? Many lights have trouble reading the MSD's capacitive discharge multiple sparks. Dial back timing lights are not recommended. Try another non-adjustable light and check the timing again."

    This brings up another question though. My timing doesn't jump all over, it stays where the gun read with little fluctuation. But the timing is very high.

    Harley
     
  3. campers1

    campers1 Registered Member

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    My guess for this would be your spitting more gas in the engine so you need to advance timing because your running richer. /forums/images/graemlins/smirk.gif
     
  4. fortcollinsram

    fortcollinsram 1/2 ton status

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    I have my Cheapie Craftsman if you need to borrow it buddy...Let me know...It is in my truck...

    Chris
     
  5. weisel

    weisel 1/2 ton status

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    I would verify the timing by using another timing light. I had a problem with too much timing on my rig (40 btdc), and it turns out, the light was giving me a false reading. A second light let me time it right. I would also check to see if the balancer has slipped and is giving wrong readings. I used a positive stop tool to find the actual tdc and verify the ballancer was correct.
    Mabey your not actualy advanced that much. Finding the correct timing will allow you to attack the carb problem properly.
     
  6. Hossbaby50

    Hossbaby50 3/4 ton status

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    I borrowed a timing light from a buddy that isn't the a dial kind, just a normal style, so I am going to try that one tomorrow.
     
  7. DesertDueler

    DesertDueler 1/2 ton status

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    I agree on the balancer as well. If that balance has moved, I could say you have 50 degrees of timing, and could only be 20.

    Dan /forums/images/graemlins/burb.gif
     
  8. Hossbaby50

    Hossbaby50 3/4 ton status

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    How exactly do i tell if the balancer has slipped?
     
  9. uglychevyZZ4

    uglychevyZZ4 3/4 ton status

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    you need to find out the following:
    there is a chevy small block with side tab, and a top tab, and the cheapo after market cover dont have one on it, figure out what you have b4 delving into this
    " slipped balancer " crap. it is keyed and it is also bolted, and pressed on, that is about as common as a Wh*re in sunday school. if you cant even read what you have, dont look for impossabilitys yet. any Chevy manual will tell you which year has which tab where. /forums/images/graemlins/deal.gif
     
  10. DesertDueler

    DesertDueler 1/2 ton status

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    Just an FYI, you could weld a balancer for all I care onto a crank, but it can still slip. A balancer is two pieces of metal with a rubber ring in between. What happens is the rubber starts to go bad, and the outer part of the balancer moves a little off of what the inner part did. Well thats how the timming mark gets off /forums/images/graemlins/grin.gif

    Dan /forums/images/graemlins/burb.gif
     
  11. DesertDueler

    DesertDueler 1/2 ton status

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    As for seeing if it has sliped, look at the rubber and see if it is torn at all, also there should be two little punch marks on the balancer, one on the inner ring, one on the outer. The should match up, if not then the balancer is bad.

    Dan /forums/images/graemlins/burb.gif
     

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