Vacuum pressure

At what rpm do people see their vacuum pressure drop below an acceptable
level(3.2?).
I also have a standby vac with a low vac pressure red warning light. When I
reduce power
to 1200-1300 rpm the vac pressure drops off and the red light comes on. I
thought in the
past the pressure would hold until around 1000 rpm. Does this seem to be
working properly?

TIA,
Pete

"Peter MacPherson" wrote in message =
news:rrluc.26283$n_6.22507@attbi_s53...
At what rpm do people see their vacuum pressure drop below an =
acceptable
level(3.2?).
I also have a standby vac with a low vac pressure red warning light. =
When I
reduce power
to 1200-1300 rpm the vac pressure drops off and the red light comes =
on. I
thought in the
past the pressure would hold until around 1000 rpm. Does this seem to =
be
working properly?
=20
TIA,
Pete
=20
I see 5 inches Hg at ground idle, either engine alone.
Normally, your vacuum regulator should be able to maintain that.
Check for leaks in your vacuum plumbing.
---JRC---