I managed to get out to work on my emissions problems for a little while
again yesterday. I only find the time to mess with this about once a
month but, it'll have to do:-)
I've been over all the points folks on this list have suggested with no
luck thus far. The idle speed remains somewhat erratic, varying between
950 and 800 over a period of 5-10 seconds. Every once in a while it
will stumble and appear ready to stall before recovering but, that's not
a frequent thing. As people have suggested, it does seem like a vacuum
leak but repeated attempts to find a leak using an unlit propane torch
have found nothing.
My vacuum advance is disconnected and non functional so I have the
timing set to around 12 degrees BTDC. Dwell is 37 degrees.
I'm not sure where the vacuum advance is supposed to connect to so I'm
wondering if the point where the hose for the vacuum advance on the carb
is not plugged. However, I can't seem to find the point on the carb
where the vacuum advance hose would normally connect. Would this
matter?
I also noticed adifference between the 2 carbs. On the front cabr,
there is a small spring loaded lever on the left side(opposite side from
the temp compensator). My manual calls this a vent lever. Basically,
at idle it seems to keep a small metal rod in the carb pushed in. Off
idle, the lever rotates slightly allowing the rod to extend a quarter of
an inch out of the carb. I have to assume this is some form of vent
that is closed when the engine is at idle. Anyway, the vent lever is
missing on the rear carb. The mounting point is there, the small rod is
there but the lever is missing. Manually depressing the rod when the
engine is at idle does not seem to alter the engine's bahevior. Idle
speed doesn't smooth out.
The next oddity is the whole emissions/carbon canister setup. My carbon
canister has 3 connections on the top. When facing the front of the
car, the rightmost connection goes to a hose the runs under the carbs,
branches into 2 hoses which are connected to the carbs right at the
intakes. The middle connection is not connected to anything. The
leftmost connection goes to a hose that runs underneath the car and back
to the gas tank. Running off the valve cover is another hose which
braches into 2 hoses which connect to nipples on the rear of the carbs.
These hoses do not have clamps on them. However, if I pull one of the
hoses that from the valve cover line off of one of the carbs, the engine
will stall. All of the diagrams I have in my manuals show that the
hoses that come from the valve cover should branch 3 times, one to each
carbs and one to the carbon canister. I have to wonder if these hoses
are somehow not connected right and causing some or all of my problems.
If it would help I'd be happy to take a picture so someone can look at
this and let me know the proper way to connect all this stuff up.
That's provided of course that it really makes much of a difference.
Beyond these few things I'm at a bit of a loss as to where to turn next.
I agree that this acts like a vacuum leak but I can't for the life of me
find a leak using the propane trick.
Any thoughts?
Phil Beckman
73 TR6
Libertyville, IL
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