Malcom :
If you were able to pull a 1/2" spark at all, I'd say the coil is OK,
and the condensor is the most likely culprit. Also check the points,
wiring, etc.
If you have an ohmmeter, you can check for 4-6 ohms between the low
tension terminals (for a stock coil with internal ballast), 10-20K ohms
between the center terminal and either other terminal, and an unreadably
high resistance between all terminals and ground (with the wires
disconnected).
If you don't have an ohmmeter, I'd strongly suggest buying a cheap
digital multimeter. HF frequently has them on sale for $10 US. I find
it makes a wonderful talisman to repel Lucas Prince of Darkness, or at
least lessen the severity of his attacks. I keep one in the trunk at
all times <g>
My suggestion to save $$$ would be to go to the local junkyard
(preferably the "pull your own" type) and get the coil and ballast
resistor off a 60's or 70's Mopar product. (GM or Ford coils will also
work, but they usually don't have the nice ceramic ballast resistor.)
Should be able to get both for under $10, I'd think. The coil will fit
in your existing bracket (you may need some cardboard or duct tape to
fill the gap), and the ballast resistor needs to be connected in series
with the hot wire to the coil.
Randall
Malcolm Walker wrote:
>
> Well, the Lucas gremlins are preparing to rear their ugly head (must have
> heard my pondering the switch to a Chevy HEI distributor)
>
> My TR4 is hard to start when cold. When hot, it (sometimes) has a bit of
> a miss on start-up. This just appeared 2nd drive ago (Sunday).
>
> I'm suspecting the coil or condensor (oh no! Not that thread!!!) ...yes,
> I know they're different. I am going to replace the condensor first
> because it's cheap. I may bite the bullet and replace the coil too as the
> one currently on the car is looking quite ancient (BTW, it's got a little
> screw in the center terminal too- Maybe it holds the "lid" on?)
>
> Replacement coil from parts house in town is $50 cdn (+tax...). It is a
> Blue Streak.
>
> I can probably get an MSD or Crane hi-power coil from them, which will
> probably set me back $80 or more. :-(
>
> Any ideas on how I test the coil? I tried the 1/2" of airspace-crank
> motor (no sparks), then 1/4" of airspace (no sparks) -- this while the car
> wasn't starting. I haven't tried it since it ran- had to yank the choke
> and it came to life. Hmm... <running outside>
>
> OK, we do have sparks at cranking speed, with 1/2" of airspace... but it
> is not fat, bright, or blue- thin, and yellow.
>
> As I'm on a Starving Student's budget I don't really want to buy a coil
> just to see what happens. Is there any way to diagnose it at home?
> Should I pull it out of the car, and take it to a shop?
>
> thanks in advance,
> -Malcolm
> * There is a FAQ for this list! Its temporary home is:
> http://www3.bc.sympatico.ca/walker/triumph/trfaq.htm
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