There are comments on the Internet about the starting limitations of 1970's style Bosch European (Volvo, Peugeot etc) ignition systems that used oil filled cannister coils, and 5,000 ohm resistor connectors to fit on top of spark plugs, and 5,000 ohm resistor in the rotor. Apparently the main purpose of this design was to give very high interference suppression and very long life of rotor cap, rotor and plugs, at the expense of reducing spark energy and more difficult starting in non-optimum conditions due to weather and car ageing (eg compression, air-fuel mixture, timing, battery, etc). Ignitions have come a long way since 1970!

The rotor modification involves removal of its internal resistor and replacing it by a copper wire to increase spark plug burn current. This extra burn current gave almost instant firing for a cold engine with Bosch W6DC plugs gapped 0.7/0.8 mm (as recommended for Volvo) on both LPG and gasoline for my 1979 244 and gave no interference on FM radio. Much improved starting. (Yes, prior to the mod ignition was checked out on an oscilloscope, and timing and fuel pressures etc checked OK, etc)

Extra burn current is supposed to increase radio interference (not found on my radio), somewhat reduce spark plug life by electrode erosion, and slightly reduce burn time with standard inductive coil ignition, and increase electrode temperature, so might have to go to cooler plug? W5DC? These appear minor issues compared to quick and reliable starting.

The mod technique and steps is shown in great detail with many photos at:
http://huelsmann.us/bugman/RotorTech.html (This site which I chose for its photos considers it a "racing" mod with CDI ignition but other sites (without photos) consider it a mod suitable for plain old inductive ignition systems.

If anyone knows of a drop-in replacement zero resistance rotor (as there are many zero resistance rotors on the market) to replace the 5,000 ohm OEM Bosch 1 234 332 215 (GB782) or a lower resistance 1,000 ohm rotor (these are on the market too) please post. An alternative to make a zero resistance rotor maybe screwing a shaped brass plate on top of the existing rotor (since resistor removal is difficult)? Has anyone on BB done this mod(s)? Or other ignition mods for a 244.

"sutherml" with a very high mileage 244