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 Tricks?

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by Rooba, Jul 21, 2001.

  1. Rooba

    Rooba Registered Member

    Joined:
    May 8, 2001
    Posts:
    28
    Likes Received:
    0
    Location:
    Portland, OR
    I've been having problems getting the timing right on my truck. The unidentified cam is not stock so the factory setting of 4 pretty much kills the engine. I'm running an Edelbrock carb and I think I have that adjusted correctly. The main problem is when I have the engine purring like a kitten, the truck won't start again if I shut her off. When I adjust it to get the truck to start... The engine idles at about 800RPM and bogs down at about 1400-1800RPM's unless I give her a little more gas, but runs fine otherwise... even when I hit the mountains. Does anyone know of any tricks or am I stuck doing the Dr. Frankenstein method of trial and error?

    Thanks,

    Cpt. Rooba
     
  2. Klef72K5

    Klef72K5 1/2 ton status

    Joined:
    Apr 8, 2001
    Posts:
    249
    Likes Received:
    0
    Location:
    Columbia City, Indiana
    when you say it will not start is it cranking over hard? if not then i would say you have a carb problem. if you set the timming so when you turn off the key it doesn't keep on running on you and to where it cranks over easy you will be fairly close.

    <a target="_blank" href=http://wsphotofews.excite.com/031/rw/Jo/og/t488200.jpg>http://wsphotofews.excite.com/031/rw/Jo/og/t488200.jpg</a>
     
  3. JST12

    JST12 1/2 ton status

    Joined:
    Aug 29, 2000
    Posts:
    192
    Likes Received:
    0
    Location:
    Garland, TX
    If the timing is good enough to get a good idle but won't restart, it does sound more like a carb issue. Have you verified that there are no leaks? You could plug your PCV ports, disconnect and plug the vacuum advance port and retry. The usual issue with incorrect timing is either a lack of power at all RPMs on one side of the adj or pinging on the other, but I don't think you'll get a bogging of the engine at 1400 rpm. Is your Edelbrock carb new? There is a pretty good troubleshooting guide telling about the possiblity of new step down springs needed, etc... Good luck. JT
     
  4. Rooba

    Rooba Registered Member

    Joined:
    May 8, 2001
    Posts:
    28
    Likes Received:
    0
    Location:
    Portland, OR
    Thanks Klef &amp; JT,

    I reset the timing on the truck so it has a good idle, but I couldn't get it to stop exactly when I turn the engine off. It starts hard now, but at least starts... we'll see if it starts when it's cold tomorrow though. As for the carb. I don't see any leaks. When I reset the timing today, it doesn't bog down at all. I'm just worried about the cold start. Oh yeah... The Edel. carb is only a year or two old according to the guy that I bought it from. I bought a new fuel filter for it as well. I'm going to read the manual I downloaded tonight and see if I'm smoking crack or if I'm doing it right.

    Thanks again for all the help... Any other words of wisdom very welcome. I'll keep you updated.

    Cpt. Rooba
     
  5. 72jim

    72jim 1/2 ton status

    Joined:
    Jul 2, 2001
    Posts:
    110
    Likes Received:
    0
    Location:
    tempe,az now in portland oregon
    sounds like the same problem i had with my truck. i put a new carb on and didn't realize i needed to plug the vacuum advance when setting the timing. after i pluged it i was able to set it without a problem.i have a mild rv cam and it runs good at 12 degrees advanced

    &lt;P ID="edit"&gt;&lt;FONT class="small"&gt;&lt;EM&gt;Edited by 72jim on 07/23/01 05:47 PM.&lt;/EM&gt;&lt;/FONT&gt;&lt;/P&gt;<P ID="edit"><FONT class="small">Edited by 72jim on 07/23/01 05:49 PM.</FONT></P>
     
  6. tshiko

    tshiko Registered Member

    Joined:
    Apr 13, 2001
    Posts:
    26
    Likes Received:
    0
    I think that 72Jim is right, it sounds like a vaccum advance problem, make sure the vaccum plate moves freely on you distributor. While the Engine is off, pull the vacuum line off the carb/mainfold and suck on it to make sure the distributor responds properly. Good Luck!
     
  7. Klef72K5

    Klef72K5 1/2 ton status

    Joined:
    Apr 8, 2001
    Posts:
    249
    Likes Received:
    0
    Location:
    Columbia City, Indiana
    If it's starting hard your off on your timming still. The guys are correct also about the vaccum advance.

    <a target="_blank" href=http://wsphotofews.excite.com/031/rw/Jo/og/t488200.jpg>http://wsphotofews.excite.com/031/rw/Jo/og/t488200.jpg</a>
     
  8. Rooba

    Rooba Registered Member

    Joined:
    May 8, 2001
    Posts:
    28
    Likes Received:
    0
    Location:
    Portland, OR
    All,

    Thanks a bunch! It started up on the 2nd crank, which is super progress. When using a manual choke, should you leave it fully on after it starts, back it off to about half, or shut it down? I've been shutting it off completely, but the truck will die if I take my foot off the gas. I think I have the distributor in the right place, now I'll just mess with the carb. for a little fine tuning. If any of you are ever out in Oregon... I owe you a beer. :)

    Just curious. I head to the mountains almost every weekend. Should I be making the mixture on the carb a little rich? Difference in altitude is about 5000 feet between my house and my weekend stomping grounds.

    Thanks again,

    Cpt. Rooba
     
  9. Klef72K5

    Klef72K5 1/2 ton status

    Joined:
    Apr 8, 2001
    Posts:
    249
    Likes Received:
    0
    Location:
    Columbia City, Indiana
    I never thought to ask if you were using a choke. try pumping twice before you start it. I took my butterfly and choke off cause when I get to playing too hard the dang thing would start to close on me and I would loose performance.
    I cann't help you out about the altitude problem, I'm in Indiana! We don't grow mountains!......lol. GOOD LUCK!

    <a target="_blank" href=http://wsphotofews.excite.com/031/rw/Jo/og/t488200.jpg>http://wsphotofews.excite.com/031/rw/Jo/og/t488200.jpg</a>
     
  10. Steve_Chin

    Steve_Chin 1/2 ton status

    Joined:
    Mar 6, 2001
    Posts:
    1,126
    Likes Received:
    0
    Location:
    Foster City, CA, USA
    With a manual choke, you should adjust it according to how warm the engine is and how cole the air outside is. If it's not too cold (50s-60s) and the engine is cold, try starting with only 2/3 of the choke applied. Once the engine is fired, let it run about 15 seconds and back it off to half-way. Let it warm up for another minute or so and you should be able to back the choke off pretty much completely unless you're running a big cam (more than about 225 degrees at 0.050" intake duration).
     

Share This Page