I made a little more progress on this before I ran out of time this
weekend.
On the Dwell issue, I discovered that I connected the meter wrong. I
had placed the red lead on the positive terminal of the coil instead of
the negative terminal (closest to the distributor). When I connected it
right, the dwell was 37 degrees. Still not perfect but, certainly a
much more reasonable number.
I also looked at the timing again and I'm fairly certain it is currently
set to 4 deg BTDC. I tried resetting the timing to 4 deg ATDC where it
belong but the engine really ran rough when I did that so, I set it back
closer to 4 deg BTDC. The engine is running more smoothly now but still
not as smoothly as I'd like. The idle speed now varies about 50 RPM
instead of 150.
One other thing I've noted is that the vacuum unit on the distributor is
disconnected. The 2 ends for the vacuum line (the unit itself and the
connection on the engine) have been plugged. I have no clue why the
mechanic would have disconnected the vacuum unit unless it is not
working correctly. Could this be at the root of my problems with
setting the timing where it belongs at 4 deg ATDC?
So, it seems like I've made a little progress but still have a ways to
go before I really understand what's been going on under the hood of my
car for the past 8 years when I wasn't trying to work on it myself. I
am, however, having a lot of fun getting back into working on the car
myself after so long away from it.
Phil
'73 TR6
Libertyville, IL
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Sally or Dick Taylor
Sent: Saturday, July 02, 2005 7:52 PM
To: 6pack@autox.team.net
Subject: Re: More emissions news
Phil---The propane test is fairly reliable if you can direct it close
enough to a leak. Wiggle the shafts to expose any worn area, to be sure.
Is it possible that the "55" you looked at on the dwell meter was the
marking for a four cylinder engine? If so, this would be close to 37
deg. for a six, and close enough. (I don't think one can get the point
gap this small as to register a dwell this long on a six, as it only
leaves five deg. for them to be closed).
With the vacuum line plugged, try setting the timing at 12 deg. BTDC.
(This should speed up the engine idle) Then reconnet the vacuum line if
desired.
For sure, the engine is hunting, if the span is 150 rpm at idle. If the
points gap and timing is correct, I'd look for an air/fuel mixture on
one or both carbs to be the cause. Other less likely causes might be
incorrect valve lash settings, or a vacuum leak thru the manifold
gaskets. (Do the propane test here, from underneath)
Let us know the outcome!
Dick
'73
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