Hi, I am running an 87 22r MT. I am trying to time it after a head gasket install. I disconnect the 2 vac lines going to the vac advance and plug them. I then start the engine and set the timing to 0 deg. When I then reattach the vac lines the timing does not change.

I suspected the vac advance diaphram and removed the dashpot and applied a vacuum to the forward most (top) vac nipple and the arm inside the dist. moved. I applied a vacuum to the rear (lower) vac nipple and there was no arm movement and it felt like I was losing a vacuum.

Is this indicative of a failing vac advance or is this reaction typical?

Thanks for the help

-Pete