I'm wondering if my vacuum advance system is working properly.
My car has a lag on acceleration. Its not terrible but its most noticable when cold. The engine runs great otherwise. The tune-up parts are all in good condition. I've kept the throttle body clean and have also cleaned the injectors. The fuel pressure is also good.

I rerouted the vacuum tubing back when I replaced the engine wire harness and have verified the tubing integrity.

I see the timing advance when I remove and reinstall the hose from the diaphram at the ignition mudule but I wonder if the diaphram might be leaking. When I test the diaphram with a hand vacuum pump, it leaks down.

Is this normal?

I haven't been able to check another one to compare with so I'm not sure if this is normal.

I might just get one from the pick n pull so I have a spare on hand.

Any help is greatly appreciated.