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Discussion Starter · #1 ·
I just stumbles across JYG artical on rotor phasing but was wondering what the symptoms would be if your phasing was off. Hard starting, hi RPM miss, hard to set timing within normal range without a lot of pinging?
 

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If I remember rotor phasing correctly you shouldn't have a problem with your setup. I think it only applies to the Jeeps with the pickup on the flywheel.
 

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Do you mean if your rotor is not pointing to the middle of the terminal at TDC. Just a guess but if it is too far advanced or retarted you would get cross firing and misfires.
 

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On a conventional distributor that shouldn't be possible without making some modifications. To rotate the cap you have to rotate the whole housing, which will take the points or pickup along.

Except for the vacuum advance moving the breaker plate in relation to the housing, the ignition will always fire with the rotor in the same position relative to the cap. You would have to reposition the cap or the breaker plate to get the rotor out of phase.
 

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Discussion Starter · #6 ·
That's right, it the position of the cap terminal relative to the points or pickup. I have a '79 motorcraft distributor that doesn't seem to have any stops for the plate where as my 84 Distributor does.

You can adjust your timing by moving the cap and pick-up but this changes it relative to the cam or crank.

I was just wondering what the symptoms are..
 

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Most of the time the symptoms are things like burned outer sides of the rotor nose, a kind of hesitation where the engine seems like it want's to go, but just can't quite get it up, or sometimes a sound like detonation (pre ignition) in the combustion chamber.

Relating to Jeeps, I find most of the problems with the HEI distributors that people have scabbed in.
There is a front and back to the V-8 distributor gear, so a lot of people are starting out with a 13° to 42° (crank position) problem right off the blocks.

Lot's of 'Red Dust' inside where the secondary has been seeking ground inside the cap.
When the secondary can't find a proper discharge point, you see the coil voltages spike until there IS a discharge, and it's usually uncontrolled then...
 
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