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Ignition issue

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Old Jul 6, 2015 | 01:18 PM
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Default Ignition issue

There is a lot of questions from a newbie
Timing set to 14 initial.
When i check timing before the engine gets really hot it is spot on.
But when it gets really hot, the timing mark wanders off, comes and goes, i can barely see it.
Could it be the torsion damper that is the problem??
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Old Jul 6, 2015 | 01:23 PM
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Originally Posted by clwi
There is a lot of questions from a newbie
Timing set to 14 initial.
When i check timing before the engine gets really hot it is spot on.
But when it gets really hot, the timing mark wanders off, comes and goes, i can barely see it.
Could it be the torsion damper that is the problem??
Do you have the vacuum advance disconnected?
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Old Jul 6, 2015 | 01:39 PM
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Do you have a points style distributor or HEI? If it's HEI the unit may be going bad, and the heat might worsen the problem. If it's a points style unit, it might be the capacitor or the coil that's being affected by the heat.
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Old Jul 6, 2015 | 01:39 PM
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Originally Posted by JimLentz
Do you have the vacuum advance disconnected?

Yes, 600rpm in drive.
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Old Jul 6, 2015 | 04:08 PM
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Originally Posted by clwi
Yes, 600rpm in drive.

If your damper has over 100,000 miles on it I strongly recommend replacing it with a modern damper from Summit Racing. The new dampers use a type of silicon rubber instead of the natural rubber and they last forever (well, almost forever anyway) and they come with timing marks every 90 degrees for setting valves.
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Old Jul 6, 2015 | 04:51 PM
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New Hei and a new coil. Well, the milage is unknown, would not trust the odometer since i do not know the history of the car...
Traced it down to Virginia 1999, but it ends there...
Other than that the car is in grate shape, dispite of history
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Old Jul 7, 2015 | 08:13 AM
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Is the HEI power lead connected to 12 volts? It can't be the damper causing the timing to fluctuate with heat. Could it be the induction sensor on the timing light? I still think it's the HEI unit.
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Old Jul 7, 2015 | 08:47 AM
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what or which parts of the HEI are new? on the HEI distributor, the pickup coil moves and flexes the wires inside, over time, they wires can get damaged internally. that is one area to look at for erratic timing.
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Old Jul 7, 2015 | 11:00 AM
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HEI looks like one from Summit, no brandmarkings...
Coil is 2years old.
Voltage to the coil is a bit of a mystery...12,7V when engine is shut off.
At idle it is 11V and when i rev it the voltage goes down to 10,5V?
Tried to feed the coil with an external wire and the idle was still erratic and timing mark off and on....
Will go to autoelectric shop for a check to rule that out, next step after that is the torsion damper. Timing light flashes just fine, don`t think that is the issue.
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Old Jul 7, 2015 | 11:11 AM
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Originally Posted by clwi
HEI looks like one from Summit, no brandmarkings...
Coil is 2years old.
Voltage to the coil is a bit of a mystery...12,7V when engine is shut off.
At idle it is 11V and when i rev it the voltage goes down to 10,5V?
Tried to feed the coil with an external wire and the idle was still erratic and timing mark off and on....
Will go to autoelectric shop for a check to rule that out, next step after that is the torsion damper. Timing light flashes just fine, don`t think that is the issue.
Are you sure you are checking correctly? coil should not be getting voltage at all with engine off...if it was, engine would not shut off.

here is a good link to checking HEI setups.
http://macsblognotes.blogspot.com/20...on-system.html
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Old Jul 7, 2015 | 01:19 PM
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Originally Posted by gungatim
Are you sure you are checking correctly? coil should not be getting voltage at all with engine off...if it was, engine would not shut off.

here is a good link to checking HEI setups.
http://macsblognotes.blogspot.com/20...on-system.html

Yes it does with ignition on..
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Old Dec 30, 2015 | 11:35 AM
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whoops. wrong thread...

Last edited by gungatim; Dec 30, 2015 at 11:36 AM. Reason: D'oh!
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