Any spark experts out there? I am left guessing on this one: Everything
on this TR6 is rebuilt, there are no vacuum leaks that I can find. If I
put in a new set of spark plugs, my 74 TR6 will run perfectly for about
500 or so miles. After that it starts missing at low RPM when under
load. The problem will get progressively worse until I replace the
plugs. When I remove them, they look clean. The insulator is basically
white with the slightest dusting of dark combustion material near the
tip and the electrodes look to be in perfect condition with a slight
whiteish dusting on them. They are gapped correctly. All of the plugs
look pretty much the same. I am using non-resistor NGK this time. The
car has a crane XR700 and putting points back in made no difference. It
has a new coil but that made no difference. The wires are pretty new and
came from Moss so I assume they are correct. I can say that this problem
is quite repeatable. I am guessing that the spark is not happening in
the correct place on the plug?
I don't get it, without visible wear, what could be going wrong?
Thanks for any insight.
Regards,
Steve
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