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'79 Spitfire Emission/PCV stuff beyond my comprehension

To: triumphs@autox.team.net
Subject: '79 Spitfire Emission/PCV stuff beyond my comprehension
From: Alan Coleman <alanco@sybase.com>
Date: Tue, 12 Sep 95 10:51:13 PDT
Hi folks,

I've been monitoring the list for a few days now.  It's sure nice to see that I 
am not alone in my Quixotic pursuit of 
driving a roller skate with a motor.

So I've owned this thing (Burgundy '79 Spit) about a year and a half now, and I 
think (hope, pray) I'm coming to the 
end of all the DPO stuff I have to undo.  But I have one that mystifies me. I 
read the article on PCV and I believe I 
understand it, but I still don't understand the behavior I am observing.  Here 
it is:

On the '79 spit, the PCV and gas-fume-recirc stuff works as follows, I believe:

Valve cover has an outlet hose that Tees into the carb on air-cleaner side of 
butterfly.  Other piece of Tee goes to 
main (center) hole in one of the two charcoal cannisters.  One of the side 
holes in the charcoal cannister goes to the 
float bowl vent.  The other goes back to the gas tank vent.  On the bottom of 
the cannister is a big hose that goes to the 
anti-runon valve, and also to the other charcoal cannister.  All holes in the 
top of that other charcoal cannister are 
plugged.

I checked the anti-runon valve and it is always closed (ie it never vents 
anything to or from the intake manifold) so I 
know I gotta get a new one, but I don't think it explains my Mystery Problem 
(question 3).  Tested by sucking/blowing 
on valve hose with car running and not running and manifold port to valve 
blocked.

My questions.

1.  Is the above described configuration correct?

2. Does it matter which little side hole in the top of the cannister I use, or 
are they the same?

3. The real problem:  If I hook up the hose to the float bowl, the car refuses 
to idle.  There is constant (albeit slight) 
vaccuum when all the holes in the cannisters are plugged, and this seems to 
prevent fuel from being sucked past the 
piston/needle thing (note sterling use of technical terminology) into the 
engine.  In other words, I think the car starves 
for gas if I hook up that hose.  If I seal everything else and vent the float 
bowl to atmosphere, the car runs better than it 
ever has.  Can anyone provide guidance on this?

Presumably irrelevant information I'm including here cuz somebody might ask:
- Deceleration bypass valve always acts wierd (ie idle stays up around 13-1400 
sometimes no matter what I do with it, 
but it looks fine when I take it apart)
- Did carb-cleaner test for vaccuum leaks everywhere and I think I've killed 
them all.
- Carb needs to be set to very lean (1/32" of needle adjust holder thing 
showing below bottom of carb piston)
- compression was even last I checked (a few months ago).  Don't remember the 
numbers, though.
- Miles on car are approx 64K.

Thanks in advance,

AC

'79 Spitfire, '86 VW GTI (which has actually stranded me more times and in 
worse places than the Spitfire)


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