440 vac leak??
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

440 vac leak??



Tried carb cleaner, starting fluid, propane, curses
and hot air.  nothing makes a change.  I even put a
propane torch (not lit) directly in the primary with
the car running and it did not change the idle???

The PVC valve rattles and has a strong vacuum on it.

I'm convinced it is a fuel/air thing.  Either a vacuum
leak or the carb.  Wish I had a spare carb.  Btw, its
a rebuilt (store bought rebuilt) Thermoquad.

Kerryp
  
--- bandmgrinding@xxxxxxxx wrote:
> 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
> > 
> > __________________________________________________
> > Do You Yahoo!?
> > Yahoo! Sports - live college hoops coverage
> > http://sports.yahoo.com/
> > 
> > 


Home Back to the Home of the Forward Look Network


Copyright © The Forward Look Network. All rights reserved.

Opinions expressed in posts reflect the views of their respective authors.
This site contains affiliate links for which we may be compensated.