Strange vacuum leak

["John Hofstetter" <hofs@domain.elided>]

Russel,
If it were me, I'd be happy with the 16 lbs. vacuum and not worry
about the anomaly of the no-change when port is opened. If I were John
L. I'd worry about it mostly for the sake of having something to worry
about. If you aren't getting any speed-up when spraying the carb
cleaner onto the top of the engine, you cant' have much of a leak.
Also, if you are getting 16 lbs. vacuum, you can't have much of a
leak. 

I've got to go now, because John L. has me worrying about theoretical
rotor phasing, and I've been moving distributor parts in my mind at
night rather than sleeping. So in regard to your vacuum, don't lose
any more sleep over it. 

Actually, this just came to mind. Check and make sure that the vacuum
advance is working. This will accomplish two things. 1. You'll find
out if you have a vacuum leak there caused by a hole in the diaphragm.
 2. You'll find out if you have much of a vacuum leak anywhere else
causing the vacuum advance not to work. Depending on where the vacuum
is being picked up for the advance this part of the test may or not
mean much.
Hope it goes well.

John H. 
----------
From: owner-ihc-digest@domain.elided (ihc-digest)
To: ihc-digest@domain.elided
Subject: ihc-digest V6 #814
Date: Sat, May 8, 1999, 6:57 AM


Date: Fri, 7 May 1999 20:50:13 -0700 (PDT)
From: Russel DeArman <russde_93@domain.elided>
Subject: OK, now I'm really confused!

  Well, thanks to John Landry's advice I've confirmed
what the dwell is and that it's set properly (thanks
John).
  While checking this out I decided to re-check the
idle settings on the carb., this time using a vacuum
gauge. Woah! Funny things are happening...
  I pulled off the cap to a non-ported vacuum source
on the carb, the idle never changed! I put the cap
back on, I took the cap off, no change...repeated this
process four or five times. The idle stays the same
regardless.
  So...I check the vacuum readings anyway...pretty
steady (<1mm waver) right around 16. But because of
the situation with the vacuum line I figure I must
have a pretty good size leak somehwere...where?
  I just replace all the vacuum hose when I replaced
the intake manifold (I hear everybodies alarms going
off) last week. I took a can of carb cleaner and
sprayed it over the entire upper portion of the
engine. Never a blip. Competely covered every surface
of the manifold I could get to, all vacuum lines, the
outside surface of the carb., I used darn near the
whole can...and still didn't find any leak.
Where the heck should look to next? Do I need to pull
the manifold again? Hate to do that...heavy as#$d
thing.
Please give me some words of wisdom,
thanks,
Russ