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Re: TR6 Emissions

To: british-cars@hoosier
Subject: Re: TR6 Emissions
From: paisley@central.bldrdoc.gov (Scott W. Paisley 303-497-7691)
Date: Tue, 16 Nov 93 10:14:09 MST
gavin@csis.dit.csiro.au writes:
 > The flame colour is erratic.  Most of the time it's pale blue.  Frequently I
 > get flickers of yellow or no flame at all.  The no flame is accompanied by
 > a stumble in the engine.  At one stage the plug sparked continually with no
 > flame until the engine died.  

These symptoms you describe are almost identical to mine.

Jerry Kaidor wrote:
 > **** I had this exact problem with the Clankster ( my TR2 )!  It
 > turned out to be weak valve springs.  They were so weak that the
 > installed height was the same as the free height.

That is really weak!  I should check mine, but I don't think I'm in
that much trouble.  During the rebuild, I put in a mild street cam.
I'm thinking that this might be part of the idle problem.  If so, I'm
thinking I'm dead for future emission tests.  I had my machine shop
rebuild the head complete, and asked them to check the valve spring
pressures.  They said that they were a little low, and shimmed the
springs to get them back up to stock spring pressure.  I would have
put high performance springs at the time, but TRF was OOS.  I actually
liked the idea of shimming springs as I felt they wouldn't weaken so
quickly.  Does this make sense, or do old springs just get weaker
faster?  Could I have weak valve springs (10K on engine) already!?!?
Would an increased spring pressure help with a mild street cam?  I
thought that one needed really high spring pressure to prevent
"floating" valves at high revs.  Certainly my springs can follow my
cam at idle!  Yes?

gavin@csis.dit.csiro.au writes:

 > I'm at a loss as to the problem.  Could it be the same as what Scott 
 > mentioned?  How do I determine this?  Any pointers much appreciated.

I definitely have a worn distributor shaft.  I know this because I
took off the distributor cap and rotor, and could wobble the shaft
with my hand.  It wasn't *really* loose, but noticeable.  Also, the
lobes on the shaft where the points ride are very worn.  Whether or
not an electronic ignition fixes my idle problem, it will help to
remove the worn shaft problem.  If it doesn't fix the problem, I still
win as I would rather not play with the points anymore, even if I have
to get a rebuilt distributor. :-)

Does anyone know if I should spend the extra bucks and get a
Luminition ignition?  They are optical rather than magnetic.  They run
$140 as opposed to $90 for the Crane (allison) box.  Eveyone who sells
the Luminition kit says the allison works fine, but the luminition is
better.  What does net.wisdom say?  For $140, I could get a mallory
dual point distributor.  Great.  Two sets of points?  Do I want to do
this?  Help!

The car in question is a 1975 TR6.  Now if I really want to pass
emissions, I will need to put the air injection system back on the car
eventually.  The reason I removed it in the first place was because
the air pump was making REALLY bad (scrape scrape scrape) noises when
I turned it by hand!  I've found a used pump for $50 which is said to
turn free, but I get no guarantee with it.  I also need the whole
setup from the pump to the manifold as I'm sure my old setup is pretty
much shot.  Anyone have this stuff?  Can air pumps be rebuilt?  Does
anyone do this?  Has anyone DONE this? :-)  I'm just FULL of questions
today! 

Ta ta for now,

-Scotty


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