Marcus,
I forgot which year 6 you have, but the vaccuum line should cause the timing
to RETARD at idle. The other vaccuum line starts pulling vaccuum at increasing
throttle loads, and supplies vaccuum to the advance unit. Sounds like you got
the two lines crossed, so you're advancing at idle. But I think you need to
fix the carbs first.
As you face the carbs from the RF wheel, on the right side of each carb
close to the engine are the vaccuum bypass valves. They look like little
models of Devil's Tower with 3 pozidriv and 3 flathead screws going into
the carburettor. The function of these valves is to deliver
more air to the engine under conditions of highest manifold vaccuum. That
occurrs when you are at say, 6000 rpm and you let your foot completely off the
gas. Since there's a lot of gas still in the manifold but little air flowing,
the mixture becomes rich and you get backfiring. So this little valve senses
high manifold vaccuum, and bypasses a little air around the throttle plate
until things settle down a little. Sounds to me like you have a ripped or
maladjusted diaphragm inside this valve, so you're letting air get around
the throttle plate all the time. This would cause the idling and piston
rise you describe. The diaphragms for these valves don't come in the
rebuild kit, so call your favorite supplier. They're like 6 bucks apiece or
so.
Now would be a good time to adjust you Idle air compensator valves as well.
These are located just outward from the vaccuum bypass valves, and look like
pale yellow banannas? at least that's what I think they look like. Anyway,
take them off the carb and remove the pale yellow cover. Inside you see a
Nyloc nut holding down a bimetal flat spring. The idea here is that the
bimetal spring heats up and lets a little air bypass the piston (and therefore
the jet). This is when the car is at operating temperature. When the carbs
are colder, the car runs just a little richer by itself, and this is what
allows the TR-6 to idle somewhat normally even when the choke's in and the
engine is not totally warm. Turn the valve over so that the black cone
is protruding towards you from the aluminum valve body orifice. Now put your
lips just over the top part of the aluminum orifice, and adjust the Nyloc nut
on the other side until just the point when you can't blow air into the valve.
When you reinstall the valve, make sure that the 2 o-rings that seal the valve
body to the carb are in place. One usually stays inside the carb, and the
other usually stays around the valve protrusion. Just make sure the one in
the carb isn't cock-eyed.
I'm sorry this is so long. Anyway, put the carbs back together, and setup
the idle, with the vaccuum stuff disconnected at the dist. Now, with the
car idling between 700 and 1000 and no throttle applied, stick your finger
over the vaccuum line(s) you disconnected before. The one that is pulling
vaccuum at idle is the retard line. It should stop pulling vaccuum
as you rev the engine up, and the other line (advance) should begin to pull
vaccuum as you open the throttle rapidly.
If you have two vaccuum units on your dist, and two vaccuum lines coming from
the carbs, you can determine which vaccum unit is which by turning the car off
and removing the dist cap. Connect a small tube to a vac. unit, and suck on
it. If the distributor plate moves counterclockwise, it's a retard unit.
Connect the vaccuum lines appropriately and fire the car up. Again set your
idle and time the car to 4 ATDC with the vaccuum retard line connected.
Set your idle and sync the carbs again.
If you don't have two vaccuum units, or two vaccuum lines, use the above
info to figure out what you have (it's common to have wrong dist and/or
carbs for your car). It sounds to me like you have currently a vaccuum
retard line hooked up to a vaccuum advance unit. After you match the
appropriate line(s) to their respective vaccuum unit(s), your car should
run lots better.
I hope this helps. Get back to me.
Greg Meboe MEBOE@wsuvm1.csc.wsu.edu
Dept. of Mechanical and Materials Engineering
Washington State University
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