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ignition timing
Posted: Tue Sep 29, 2015 4:57 pm
by JimmyC
Is the timing 1 TO 3 mm before or after top dead center. I have no idea what behind means. I thought it ment closer to the tailgate.
Why does the setting change with engine temperature?
Can I just advance it until I get some knock or trouble starting and then back off?
Re: ignition timing
Posted: Tue Sep 29, 2015 5:43 pm
by Jimm391730
When the mark on the pulley lines up with the pointer, that is Top Dead Center (TDC). As the engine is running, the pulley rotates away from the passenger door. So if your timing light shows the mark closer to you than the pointer (the mark is closer to the passenger door than the pointer is) then the pulley has not rotated far enough to put the mark under the pointer; this is BEFORE TDC. If the mark shows up on the drivers side of the pointer, then the pulley has rotated too far, and the timing is AFTER TDC. The distance between the mark and pointer is measured in millimeters.
The only timing item is the weights in the distributor base; if they stick, and later free up with temperature, this is the only reason I can think of that you see a change with temperature. But at idle speeds the weights should not be advancing the spark at all yet, unless one of the springs has broken.
Re: ignition timing
Posted: Tue Sep 29, 2015 6:30 pm
by waterdog
nicely explained !!!!