Greetings fellow scions -
I've always had some kind of miss or ignition, and poor idle problem on the
GT6 and never really addressed it fully ever since I rebuilt the entire car
over 6 years ago.. Since I don't drive it daily It was more of a nuisance
than a problem. This car also ALWAYS ran a little on the hot side at idle
even on cold days. And yes it does get sorta cold here. It would eat
plugs, and especially rotors with great regularity. The rotors would have
the carbon track to the shaft indicating a break down somewhere, and I knew
it was taking the easy path, but couldn't see how that was easier than
jumping to the plugs. The problem was aggravated with the addition of the
sport coil and the Crane (Allison) ignition. So before I went to the San
Diego Triumph club gathering last night, meeting in person a couple of list
members, Dave and Mel. They found me out, my 15 minutes of fame! Scary to
think someone actually reads this stuff :-) Kinda nice to put faces to the
names and a pleasure to meet them! Anyway, I decided to attack the problem
in earnest. This problem would always seem to get much worse after having
to go through all the smog testing garbage, which I just went through. Got
fed up and thought I'm gonna find out what is going on here! I set the
crankshaft to about 10 before TDC, number one cylinder firing, and noticed
that the rotor was pointing in-between the wires instead of pointing to the
required plug lead (number 1). Of course this condition would be even
worse as the ignition advances, rotor becoming farther away as timing is
advanced. AH HA! The poor spark had to decide which wire it wanted and I
believe it sometimes went the wrong way! So I reset the distributor to line
up the rotor with the number 1 spark wire contact. Good, now to reset the
Ignitor, or optical sensor. I had the cap off, all wires still connected,
and started to rotate the assembly so as to position the 'opening' to
coincide with the new rotor position. Eureka! I heard the spark crack. I
clamped the retaining screw and grabbed the rotor to check the position by
twisting against the advance springs. Sure enough, spark every time! But
where was this arcing? Very strong by the way. I thought, oh no, coil
break down internally but couldn't see any arcing plus it was awfully loud
so-to-speak. Checked all the wires for carbon tracks and still no sign.
Then while I had the cap rotated so I could see inside at the contacts.
Crack! there it was. It was arcing across the center electrode to the
spark wire electrodes, through the sparkplug to ground. And not always the
same wire. Quite a sight to see a violet spark jump across a good 3/4 of an
inch gap OVER the concentric spark barrier rings between the center
electrode and the wire electrodes! No denying I had plenty of spark voltage
and a testament to the advantage of the sport coil and electronic ignition.
In fact I suspect it was this very reason that I had a problem instead of
failure as the spark had enough potential to jump the wrong wire instead of
no wire at all. The car now has plenty of power, no missing and apparently
cured the over heating at idle. I may have had sparking problems akin to
running to much retard, causing the overheating problem and poor idle! Glad
to have that solved! Now if I can just get those vent window seals!
Anybody wanna by a bottle of this magic cure all elixer I also happen. . .?
Barry Schwartz
Bschwartz@encad.com (San Diego, CA)
72-V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire (body repair almost done)
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