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Timing tab location?

Discussion in 'The Garage' started by docgab, Jul 6, 2003.

  1. docgab

    docgab 1/2 ton status Premium Member

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    Hello again all,
    I have a 1978 K5 w/350. It didn't have a timing tab on it. I've had to give it a tune up etc and of course setting the timing was on the list. I had to put a tab on and it seems to me to be in the logical location (kidjethro thought it was in the right spot as well) but now the truck doesn't run right. The numbers given to me were to set it at 4 BTDC. When it is set there I get a strange "bwap" sound out of the exhaust and a hesitation on acceleration. I saw a post by HarryH3 today saying that GM has used two locations for the tab and I was wondering if anyone knew if mine is set up correctly. TDC on the tab is at about 2 o'clock. I can get pics if needed. Once again, thanks for your help all.
     
  2. Zeus33rd

    Zeus33rd Smarter than you GMOTM Winner

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    4* BTDC is what you need to be smog legal in CA. A federal vehicle would be 8* BTDC. Thats what I set mine at. It's simple enuff to retard it back to 4* when smog time rolls around. You might try 8* and see what happens. I can't really imagine that there would be a different location for the tab on your truck- You have it on the drivers side of the block right? Well- I guess you said 2 O'clock, so I guess it would be- Try to mount the tab one set of bolt hole's higher or lower on the timing cover and see if it looks right and lines up- It would be pretty obvious if it's wrong. /forums/images/graemlins/thumb.gif
     
  3. neverdone

    neverdone Registered Member

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    I couldn't find mine either. Try flashing your timeing light strait down behind the water pump. Mine has a round tube to sight through. Hope this helps!
     
  4. docgab

    docgab 1/2 ton status Premium Member

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    [ QUOTE ]
    4* BTDC is what you need to be smog legal in CA. A federal vehicle would be 8* BTDC. Thats what I set mine at. It's simple enuff to retard it back to 4* when smog time rolls around. You might try 8* and see what happens.

    [/ QUOTE ]

    Cool deal, thanks Joe. As far as smog time goes, it is that time! /forums/images/graemlins/shocked.gif I have one place only that seems to want to do it because of that manifold leak. Bummer.

    [ QUOTE ]
    I can't really imagine that there would be a different location for the tab on your truck- You have it on the drivers side of the block right? Well- I guess you said 2 O'clock, so I guess it would be- Try to mount the tab one set of bolt hole's higher or lower on the timing cover and see if it looks right and lines up- It would be pretty obvious if it's wrong. /forums/images/graemlins/thumb.gif

    [/ QUOTE ]

    The place I put it was a place you had recommended and it seems to me to be the only place that would make sense and it is the only place I could put it on without pulling off the fan and pretty much everything behind it! /forums/images/graemlins/tongue.gif Well, I'll set it to 8*BTDC and see what happens. Come the day of smog I'll bump it to 4*. Thanks again Joe. Oh, I got your carb book. Good stuff. I'm gonna send this one back with Dale and buy me one for myself as it might take me some time to get through it and with kids I don't trust my ability to keep yours safe for long! /forums/images/graemlins/wink.gif
     
  5. mofugly13

    mofugly13 1 ton bucket of rust Premium Member

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    HarryH3 wrote that in reply to my post. On my 73 engine the timing tab is spot welded to the timing cover with TDC just past 12 o'clock. I don't know why or when they changed timing locations, but maybe you should try retarding your timing a LOT and see if it runs better. I think 4* BTDC is right at 12 o'clock. When I get my old motor out today and all pulled apart I can send you my timing cover as I won't be needing it anymore. Lemme know if your truck runs better with the timing way retarded.
     
  6. docgab

    docgab 1/2 ton status Premium Member

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    I reset the timing today to 8* BTDC and it made a huge difference. Thanks for the recommendation Joe. Cool deal. Mofugly, I'm a bit confused though. Isn't BTDC advancing the timing so 4* is less advanced than 8*? Keep in mind I'm new to all this stuff so no surprise if I am wrong! lol
     
  7. mofugly13

    mofugly13 1 ton bucket of rust Premium Member

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    Yeah, you're right. I musta had a brain fart. /forums/images/graemlins/ignore.gif When I said retard I guess I was thinking 'bout myself. /forums/images/graemlins/blush.gif I meant advance your timing, like you said.
     
  8. Zeus33rd

    Zeus33rd Smarter than you GMOTM Winner

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    [ QUOTE ]
    I reset the timing today to 8* BTDC and it made a huge difference. Thanks for the recommendation Joe. Cool deal. Mofugly, I'm a bit confused though. Isn't BTDC advancing the timing so 4* is less advanced than 8*? Keep in mind I'm new to all this stuff so no surprise if I am wrong! lol

    [/ QUOTE ]

    Right on dude. /forums/images/graemlins/thumb.gif I'm glad I could help.

    As far as the Q-Jet book goes- You can keep it as long as you want. But if you want to get on of your own, I think I got that one from Amazon.com- I can't remember. /forums/images/graemlins/pimp1.gif
     
  9. docgab

    docgab 1/2 ton status Premium Member

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    [ QUOTE ]
    Yeah, you're right. I musta had a brain fart. /forums/images/graemlins/ignore.gif When I said retard I guess I was thinking 'bout myself. /forums/images/graemlins/blush.gif I meant advance your timing, like you said.

    [/ QUOTE ]

    /forums/images/graemlins/grin.gif lol. Not a problem. I just wanted to make sure as I am new to this all and I thought I had a grip on it and you were kinda throwing a wrench into the works! /forums/images/graemlins/thumb.gif
     

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