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New engine misfiring

Old Jan 11, 2006 | 10:57 PM
  #1  
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New engine misfiring

Well,
I'm having trouble starting my new rebuild.

This is what I've done.
Removed the valve cover, turned over until the intake valve opened and closed, then brought to TDC via the timing marks. (I know TDC lines up with the timing marks because I checked this while on the stand.) I watched the rotor rotate clockwise while turning over by hand. (It points to #1 cyl and I lined the #1 wire to this.) I put the cover and cap back on and tried to turn it over but it keeps misfiring. It's way off and I'm doing something wrong. I tried turning the rotor while someone cranked it over but it misfires big time. How far do you move the rotor to set timing anyways? Is there a lot of room for adjustment or is it very sensitive?

Can the engine be damaged if it's way off like this?
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Old Jan 11, 2006 | 11:09 PM
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The best grass roots approach I know of is to pull #1 spark plug,hold your thumb over the hole while someone bumps the starter.When compression blows your thumb off the hole,set the distributor to #1
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Old Jan 11, 2006 | 11:32 PM
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sounds like its 180 degrees off, take out your distributor, rotate it 180 degrees, plop it back in.
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Old Jan 11, 2006 | 11:37 PM
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Both makes sense.

Can it damage the engine if it's off like this?
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Old Jan 11, 2006 | 11:49 PM
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i wouldnt say so, however since its a brand new engine, i would refrain from as much failure to startup as possible.
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Old Jan 12, 2006 | 12:05 AM
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Originally posted by Scorpner
Both makes sense.

Can it damage the engine if it's off like this?
Why don't you do what I suggested,and hear it run?
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Old Jan 12, 2006 | 02:03 AM
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I have to wait until I can try again, it seems really bad and I was worried it was damaging it. Everything looked correct when I double checked it. I'll try what you've told me and see if it makes a difference.
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Old Jan 12, 2006 | 02:25 AM
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trust me on this, flip the dizzy 180 and you'll be worshiping me.

the crank moves twice for one rotation of the cam, so even though you lined up the dots, you have it firing on the exhaust stroke.
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Old Jan 12, 2006 | 11:53 AM
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Don't crank it too much, you don't want to wash the cylinders, cause then you'll be in trouble...
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Old Jan 12, 2006 | 12:36 PM
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You mean washing with fuel? What happens then? I'm already worried about what happens already.
I won't be able to do anything with it until this weekend and I hope to have a mechanic stop by to look at it.
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Old Jan 12, 2006 | 01:05 PM
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Originally posted by Irockz
The best grass roots approach I know of is to pull #1 spark plug,hold your thumb over the hole while someone bumps the starter.When compression blows your thumb off the hole,set the distributor to #1
...then bring it to TDC on the balancer. This is what I think the problem is. Do the above.

If you did stop when the intake valve had just closed, your firing the mixture while the piston is beginning the compression stroke instead of at TDC of it.

Last edited by Stekman; Jan 12, 2006 at 01:07 PM.
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Old Jan 13, 2006 | 08:41 AM
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Originally posted by Stekman
...then bring it to TDC on the balancer. This is what I think the problem is. Do the above.

If you did stop when the intake valve had just closed, your firing the mixture while the piston is beginning the compression stroke instead of at TDC of it.
No, I watched it until the intake opened and closed then rotated it to where the timing marks lined up. I'll find out what's wrong this weekend. I think it is off 180 and what I'm doing is incorrect regardless.
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Old Jan 24, 2006 | 01:45 PM
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Car: 85 SC, 86 Berlinetta
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Transmission: 700r4, 700r4
Thanks for all of your help.
It was something stupid, I don't even want to say. Let's just say I must have looked at the wrong diagram.

It runs great now, just have minor things to take care of and I'll have a daily driver with a whole new drive train behind it.


Thanks again.
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