440 vac leak??

[bandmgrinding@xxxxxxxx]

Hi Kerry,
    Have you tried the old spray carb cleaner around the manifold to see
if it increases RPM ? Have you checked to see if you have the right pcv
valve? Try blocking off the pcv and brake booster lines and see if it
runs any better. What carb is on it? Sounds more like you are running
rich if you give it more air and it runs better. Have you checked for a
plugged exhaust or collapsed muffler ( not likely but I've seen it
happen)
If you have a thermoquad, I've seen these have a bowl problem that causes
this, we worked on a state troopers car years ago that had this type of
problem. Funny thing about that one was that it ran better at night than
during the day. Drove us crazy till we changed the carb, even though we
had rebuilt the old one a couple of times.
  Good Luck
   Allan R

On Fri, 15 Mar 2002 15:16:59 -0800 (PST) KerryPinkerton
<pinkertonk@xxxxxxxxx> writes:
> Well, I'm approaching stumped.  My 73 runs like crap
> and I've messed with it til I'm about out of ideas.
> 
> Here are the symptoms:
> 
> Timing set at 10 degrees BTDC with the Vac adv
> disconnected and plugged.
> 
> Vac gauge shows about 17, it used to be about 20.
> 
> I have adjusted on the carb and timing and made little
> change in the vac.
> 
> i have disconnected and plugged ALL vac lines with NO
> change on the vac guage.
> 
> The car runs right now as well as it's run recently
> WITH THE BREATHER OFF.  With the breather on it is
> very FLAT at high RPM and has a slight bog if you
> punch it at idle.  Turning the breather lid upside
> down and letting more air in helps but not as much as
> removing the breather completely.
> 
> Vacumm leak you say.  I've tried the starter spray,
> propane trick and get no RPM or engine noise change.
> 
> Compression is 130 per cyl.
> 
> Now for the interesting stuff, under some conditions
> of timing, I can screw the idle jets all the way in
> and the car still runs which makes me think vacuum
> leak.  Also the car will not idle down below about 600
> RPM even with the screw completly backed out.
> 
> Plugs are about a year old but probably don't have a
> 1000 miles on the, same with wires, rotor button, and
> cap.  Cap does not show signs of damage or wear.  
> 
> At this point, the only think I can think of is that
> there is a vacuum leak around the intake manifold,
> probably on the bottom where I can't get to it.
> 
> Before I pull it off, I'd like to hear from the wisdom
> of the group.
> 
> Oh, one piece of good news is that my 'ticking' sound
> was a bad exhaust manifold which has now been
> replaced.
> 
> Kerryp
> 
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