I'm posting this because I couldn't find any like issues, and I have never seen an issue like this in over 30 years.
I got the machine because it wouldn't start. It was only sparking on every 5th revolution. checked the crank position sensor, then 1 at a time cleaned and put dielectric grease on all connectors. I tried starting after each one. Finally it ran. Then after two weeks of starting it everyday, it went back to that spark every 5th revolution. Put in a new coil, and a regulator because it was dropping voltage to the battery while sitting. Of course I had a new plug, checked cam timing and chain, set both valves, and the injector was firing as it should with a perfect spray pattern.
I did a lot more troubleshooting and eventually it got spark every revolution, had great spray, and wouldn't even pop. Stayed this way. It was driving me nuts, wouldn't even pop with ether.
I pulled the trigger on a new ECM because what else could it be? Installed it and she fired right up, and is perfect now. Hope this helps somebody.
BigToys
