On Tue, 30 Aug 1994, Mike Ladwig wrote:
> My TR6 has been running oddly lately - every so often, under load, at about
> 2K RPM, one (two at most) cylinder will miss (completely). If I change the
> load conditions for a second, the problem disappears. I'm reasonably sure
> it's not a fuel side problem. I took a look at my distributor, and
> discovered that the rotor drive shaft has a lot of lateral play. Since
> this is my daily driver, I'm more concerned with reliability and good
> running than originality, and I thought perhaps an electronic ignition
> might be the way to go.
Missing under load is a symptom of a weak spark, and 90% of the time the
cure is as simple as a new set of spark plugs (or cleaning and regapping
the old ones).
A sloppy distributor shaft _can_ cause missing under load, since it
effects the cam dwell, which effects coil saturation time, which effects
spark strength. However, start with cheaper and easier possibilities
like the plugs and plug wires.
The sloppy distributor _does_ need to be taken care of, though, even if
other cheaper fixes stop the missing, because the slop adversely effects
the accuracy of the spark timing, which adversely effects power and economy.
Installing an aftermarket electronic conversion in the worn distributor is
a waste of money, since the shaft wobble will still mess up the accuracy
of the timing. Whether you stay with points or go electronic, you need
to rebush the distributor and may need a new shaft as well.
Installing a distributor meant for some other BritCar car isn't the
answer, either. Even if it is the same model of Lucas distributor,
there's no guarantee that the advance curve will be correct for a TR6
unless it came out of a TR6.
Don't Moss Motors and The Roadster Factory both have rebuilt distributors
available in exchange for your old one (plus a bunch of money)?
-----------------------------------------------------------------------
Chip Old 1948 M.G. TC TC6710 NEMGTR #2271
Cub Hill, Maryland 1962 Triumph TR4 CT3154LO (daily transportation)
feold@umd5.umd.edu
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