Hi,
I'm trying to debug a misfire problem and I need some advice.

I have a vacuum gauge tapped into a "T" on the vacuum line going into
my fuel pressure regulator.  I don't know how to perform at proper
diagnostic.  Any advice?

At idle warm, I get 8" hg.   At idle hot, I get 12" hg.

At higher RPM, I get consistently 19" Hg.

At low RPM (idle), the needle wavers.  My tach needle also wavers.  I
have a misfire in one of the cylinders.

Compression on cylinders 1,2,4 is 150psi.  Cylinder 3 is 130psi.

-- Craig