The next day, another mechanic friend comes over to check over the bus. He drives a killer “rat look” splittie and it’s completely full of tools.
The alternator is now the top priority on our list and it immediately gets pulled out. Brushes are good, so the internal regulator is the diagnosis. They hop into their car and run to get another one and return and put it all back together. Still no good. Regulator is still the diagnosis. They hop back in to the car and go get another one. After putting in the second one, it seems to be fixed. This takes most of the day, but we’re still missing on #1.
At idle, you can pull the #1 plug wire and nothing happens. It seems to work at higher rpm. We replace the wires and plugs… again… and still no change. You can pull the plug wire off the cap about 1/4” and it seems to start firing at idle. Plug it back in and nothing (this is why the other guy suggested increasing plug gap and tightening the valve.) It seems to be electrical and we decide to drive it a bit and fully charge up the battery with the rebuilt alternator and see if it’s related. I can’t help but think it might also be the carb, but since #1 and #2 share an intake and #2 is fine I’m not sure how to explain it (same for #3 and #4.) Juan knows a carb guy, but he’s not available for a few days. The mechanic jokes that after 180 km the problem will go away. Good enough for now. We tweak the carbs again and call it good enough to continue moving on.
Symptom: seems to be misfiring on #1 (less on #3) at low RPM. You can put an inductive tach on the #1 and #3 wire and it seems to be missing (bad readings, intermittent strobe). #1 and #3 plugs get black and carbonized. #2 and #4 are tan/gray and look fine. We’ve got a 009 dizzy (timed at 30 deg full advance and 7 deg at idle) and Dual Kadron carbs.
The problem seems to mainly be when the engine is cold and idling
Compression is 110 psi on all four cylinders.
All valves are at 0.006”
New coil, cap, rotor, wires, plugs
Different cap and rotor and 009 distributor have been tried with no change.
Both points and electronic ignition have been tried with no change.
New plugs and wires have been tried many times.