Probably coil shorted intermittently - this is classic bad coil symptom. I
once had a coil that would fail after 5 minutes running - took forever to
diagnose since it looked so much like a fuel problem.
At 02:45 PM 11/6/00 -0500, Carl McLelland wrote:
>For you technical buffs out there, this one is a stumper for me.
>At Sears Point, October 28-29, I had an ignition problem that I'm at a loss
>to resolve. The car is a series 1 Alpine with a series 5 (1725cc) engine, 12
>volt with the polarity reversed to negative ground. The engine is basically
>stock, with Zenith carbs and a Mallory dual point distributor. I'm also
>using a Mallory ballast resistor.
>On Saturday, in the rain, temperature around 65 degrees, the car ran
>fantastic, easily attaining 6500rpm in 4'th gear. We finished 2'nd overall.
>On Sunday, on a dry track with the temperature again around 65 degrees, the
>performance was the same until the start of the 3'rd lap. At this point, as
>I was entering turn 1, the engine stopped running..... just as if I had
>turned the ignition off. All attempts at a restart failed.
>After the end of the race when the tow truck arrived to tow me in, just for
>kicks, I hit the starter and she came to life as though nothing had ever
>gone wrong. I drove it around to the pits and up onto the trailer.
>The next morning I fired it up and drove it off the trailer and into the
>shop. It started right up but the ignition cut out if I tried to take it
>over 2000rpm. The next day I started it and it ran through the entire rpm
>range without hesitation.
>The fuel system works fine; no problem here.
>The timing was correct.
>The ballast resister showed 1 ohm of resistance. The specs for the resistor
>are 0.75 - 1.5 ohms, so no problem here.
>I pulled the distributor and removed the points. One set of points showed
>correct point gap and normal pitting for the amount of use. The other set of
>points looked like they had been a plate for arc welding, with the entire
>surface of the points badly pitted and rough. The gap appeared to be
>correct; given the amount of pitting.
>I replaced the points, condensor, ballast resistor, timed it and it runs
>perfectly. Further inspection revealed one wire lead from the ballast
>resistor to the coil that "wasn't as tight as I would like (but not falling
>off, either)", which I tightened. Further, I inspected every wire and
>connection between the engine and ground or back through the circuit to the
>ignition/starting switches and no other problems.
>Has anybody out there experienced similar problems? What was your cure?
>Anybody have any idea what may have gone wrong? I'd sure hate to be at the
>front of the pack again this weekend at Thunder Hill and have a similar
>Thanks in advance!
> Carl McLelland
> email: email@example.com
> web: http://carlynneracing.homestead.com/home.html
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