After 10 years of ownership, the SLC finally leaves me stranded

During the 10 years and around 40,000 kms I’ve owned the 450SLC, it’s proven to be extremely reliable.   Sure i’ve had a flat battery once a couple of times, and a fuel pump that would cause the engine to occasionally stall until it was replaced, but it has never left me stranded, until this weekend.

About 100 meters from my driveway, the engine started to loose power and then finally died.   I was able to restart it briefly, then nothing.   Given the fuel was low, my first thought was that the tank may be dry and the gauge giving an incorrect reading.   Even after adding 10 litres of fuel from a jerry can, this didn’t do anything.

Next try was to see if twas the fuel pump relay.   The way the car died, it had felt like it had run out of fuel.   I liberated the fuel pump relay from the 280CE and tried to see if that would work.   It didn’t either.     As a note, the manuals for the SLC describe left hand drive models, where the relays are all visible just above the fuse box.   I found a lot of conflicting information on the Internet about the RHD models.   Some mention it is behind the glove box, other mention you need to remove the panel above the drivers knees/legs and the relays are under there.  At least on the 1977 model, you don’t need to do any of that, the relay can be removed by reaching up behind the kick panel, just above the fuse box.   Given how these panels are now fairly brittle, it is good to know it does not have to be removed.  Having said that, the location for the W123 is far preferable to the C107 (123 location pictured below)

Given it was not the fuel pump relay, I was running out of time, as the space I had pushed it to was becoming a no parking zone, I called the NRMA to take a look.   The NRMA guy was very good and was quickly able to use some of his test equipment to isolate the issue as an ignition issue, and most likely due to the coil.   I have never changed the coil since I owned the car, so used the NRMA man’s machine to limp the car back into the garage (up a hill, so pushing not really an option) and wait for my shiny new coil to arrive to see if that solves the issue!