I did the cylinderhead, adjusted the linkage for the throttle & injection pump and adjusted the idle mixture until the car ran just fine. A few days ago, I installed the Pertronix II electronic ignition and found that the engine didn’t like it: At low idle RPM the spark actually disappears sometimes: I can see it with the timing light. The engine then just quits. At higher RPM it’s fine, but sometimes I got some backfiring at about half throttle. At full throttle it works great. Today, I installed points again: This is a 009 alu distributor and the shaft has about .006 in sideplay. It’s a pain to get the dwell just right: At first I had it at 36º, then as high as 45º. With a lot of fiddling, it’s now about 39º. It decreases when I increase RPM. The distributor has about 10º vacuum retard at idle and I set the timing at 1º after top dead center. It idles very nice at 600 RPM (and the tachometer agrees with the electronic tach.) And it runs wonderful. I would like to have electronic ignition because the points wear and it’s such a pain to get them just right. But it appears, I can’t have it. Bummer!
'69 280SL,Signal Red,007537,tired engineer, West-Seattle, WA