View single post by Jensen Healey
 Posted: 04-27-2009 09:37 pm
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Jensen Healey



Joined: 03-11-2005
Location: San Anselmo, California USA
Posts: 983
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Let's assume you have a stock Jensen Healey distributor which is vacuum retard.

My total advance is about 17 to 18 degrees at 2000 to 2500 rpm.   10 degrees at idle and then another 8 when I boost the rpms.  This is with the vacuum attached.  Does this mean it would be at 25 if my vacuum was not attached? 

No, your vacuum retard is retarding the timing 8 degrees less when there is less vacuum, (remember high vacuum is when the butterflys are closed, like at idle and when decelerating). Of course, less retard is just the same as more advance.

Sounds like the mechanical advance is frozen.

If your static timing is set to 10 degrees the vacuum retard would retard it to 2 degrees at idle. I'll bet your static timing is set to 18 degrees.

You need to remove the distributor and send it to Jeff at Advanced Ignition. Move the engine to top dead center and note that the rotor points towards the #1 spark plug wire before removing. That way you can put it back in the same way when you get it back from Jeff.

I also recommend throwing the Crane XL Fireball 500 gee whiz POS in the trash and having Jeff install a Pertronix unit which he can setup correctly for you.

And disconnect the vacuum retard, cap the manifold, and never, ever, hook it up again!  Nobody has used one since 1975. My car runs great without it.

Kurt