I thought I would report on my conversion back to a points system from a Crane electronic module.
My car came from the previous owner with a Crane XR3000 high intensity system. He informed me that he had some running /starting issues which the Crane system seemed to cure and that he was generally happy with it. He had experienced complete failure of the module though, which resulted in a tow back to his mechanic and it was discovered that the module was full of water. This was replaced by Crane under warranty and he said he had no further problems with it. My own experience was generally good, though I suspected some of my running issues were a result of the Crane system. I had a slight miss at 2500-3000 rpm even after a head rebuild and an annoying tendancy for the revs to drop to near 0 momentarily on gear changes which made smooth shifting difficult. I also was experiencing occasional hot start problems, which when it occured made starting impossible for 30-60 minutes, unless I pushed started the car, which was very easy to do. When this occured while Dan (Benz Dr.)and I were in his town, he was sure that the spark was too weak even though I had a new red coil, plugs and wires. He offered to rebuild an 051 for me and posed the question "what will you do if the module breaks down on the road somewhere". He has a distributor calibrating machine in his shop and explained how the different systems that worked on conventional points systems had to be synchronized for the distributor to function properly.
Well I'm happy to report that once I finally got to installing the rebuilt distributor, that my car is running better than before. It has a more pronounced growl to the exhaust note, smoother running at all rpms, and I think the upper speed range is stronger too, though these are hard items to measure and I admit that I'm looking for improvements. Most significant to me was the effect on shifting. The rpms don't drop below idle anymore and this helps smooth out shifts...I no longer try to "blip" the throttle while releasing the clutch.
Mostly I like the idea that I can carry a spare set of points and get myself going if the old ones start acting up. We like to drive the back roads and this can mean we are miles from nowhere and out of cell phone range, so the thought of a ign. module caused breakdown was a concern.
Dan reported that my old dist. was suffering from almost 50 deg. of vacuum advance from improper set-up, though I hadn't been aware of any pinging, so it seems to confirm that the electronic ignition systems can improve performance when things are not set right, but perhaps that is treating the symptom rather than the cause.
I have recently realized that my hot start issue was not module related....it seems that after a highway run and sitting for 15-20 minutes, for some reason which I haven't exactly determined, the engine is flooding and the cure was to disconnect the CSV and hold the throttle wide open. This has worked everytime I've had a hot start issue for the last month. More troubleshooting required.
Any one want to buy a used Crane module
Ricardo
'67 250sl
4 speed
