> You should probably see
> between 10 - 15 lbs of vacuum at idle.
Sorry, that's not right. The vacuum advance port is 'timed', meaning it
gets no vacuum at idle. Every car I've ever wrenched on is this way,
including all TR2-4A. Only the vacuum retard port on later cars, or a
manifold vacuum port like for a brake booster or carbon canister, has vacuum
present at idle.
> You should see the timing mark
> move toward retard as you incease the throttle, then toward
> advance when you let off the throttle.
On a TR2-4, the vacuum advance moves fairly slowly, while the centrifugal
advance is working quite rapidly in the opposite direction. It's really
tough to separate the two motions, especially since the engine will rapidly
rev up with the throttle open enough to activate the vacuum advance.
> If you use the pump while the engine
> is idling, you should see a change in engine speed as you pull a
> vacuum on the advance unit.
Since the most common problem is a leaking diaphragm, also check to see how
long it holds vacuum.
Randall
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