Further to this discussion:
I've put nearly 8,000 miles on my car since the restoration was "completed" in December, 2000. Of course it's never done. I've had the Crane XR700 since the restorer installed it.
Most of those miles have been trouble free; problems began a few years ago, and were traced to a disintegrating fuel tank. That cured last year, ran fine the rest of 2005. Come 2006 an "ignition" related problem began to appear--sudden death, but quick to recover.
In the past few days I began to troubleshoot in earnest. What I found yesterday was that my ballast resistor was the incorrect value of .9 ohms; it should be .6 ohm. Don't know how or where the .9 came from it does not seem to be part of this ignition setup. This caused a low voltage at the coil + primary, out of spec. When I installed the proper ballast, the voltage went up to spec. The tech support department of Crane Cams was helping me on this yesterday.
Perhaps more revealing? The old .9 ballast, a Beru,
was cracked lengthwise down the middle. You can't see the crack when it is installed, but when in your hand looking at the back, it's there. Further to this, it appears as if the screws that go into the ballast and hold the wires in place are a bit too long; when tightened down, they contact the ceramic--causing stress where the crack is. Pay attention to detail! For some reason the ballasts don't come with screws so that's why the wrong size ended up in there.
Don't know if the dying problem is cured. It was intermittant and simply could have been the Crane box getting a bit hot and the thermal shutoff kicking on, as it has recovered. But with a cracked ballast and the incorrect one to boot, I can only have improved things.
I got the new ballast and a spare coil, rotor, cap, points (for backward conversion if need be)at All-Euro in Royal Oak, MI. They are close to me but do most of their business mail order. Prices were the best I've found. BTW the "red top" on the Bosch coil is gone, replaced by black bakelite and a RED LABEL on the silver can. The cost of these parts, including a spare Crane unit, is far less then the aggrevation of getting stuck somewhere, so my trunk has spare ignition parts; backward conversion parts and a spare Crane. Of course now that they are in the trunk I'm hoping they displaced Mr. Murphy and I'll never need them.
http://www.alleuro.com/The tech guy at Crane was GREAT. I detailed my problems in an email; he called an hour later and led me through a voltage checking process that led to the discovery of the ballast issue. If you have any problems they'll help you. I've heard similar about Pertronix support, so if you decide to go breakerless these two companies provide the support if you need it. One thing the tech guy told me to do was to open my spark plug gap on my NGK BP6ES plugs from the factory recommended of .032 to .045. I have not done this yet but will tackle that soon.
Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored