Hello peach parts, long time lurker, first time poster. I was recently tasked with bringing a '73 280 back to life after four years of improper storage. The short Story is this car has been for sale for years, and after discovering far more rust than I had hoped for in my '76 300d, I set about finding a replacement car for it this summer. This car popped up again for sale this July, so I went and looked at it and made an offer (I had looked at it for a friend in 2011, it was running then). He decided not to sell the car for sentimental reasons, but asked me if I could get it running and driving for him again.
Now that the story is out of the way, onto the technical part. He told me the car would not start a few months back. A friend put a new battery in it then it sat again. I started with changing the oil, draining the old fuel and putting a bottle cap full if oil down each cylinder and let it sit overnight before cranking. Looking into the no start issue, I found it had no spark. Pulled off cap and rotor.
Not looking too great, but they will be replaced. A quick clean with some light Emory cloth and they should be good enough to at least work enough for testing purposes. Pulled a piece of paper through the points and found little to no corrosion, so should be good there
Up next was the ballast resistors, one looked kinda crusty, so I bypassed both of them for testing purposes, no spark.
Pulled what appeared to be some sort of ignition module off the LF inner fender, it is clean inside with no evidence of burnt/failed components. When pulling the HT lead off the coil, the wire disintegrated in my hands. Hoping this was the issue I rigged up another wire to it, still no spark. Still need to properly check the coil, so if anyone has the resistance spec that would be great.
This is where I stand at the moment. All of my 114/115 experience is with diesels, I could pull one apart in my sleep, but I have zero experience with the M110/any older Mercedes gas engines. Any input into what I should be looking at next/test procedures/common fail points in this ignition system would be greatly appreciated so I can get this old girl back on the road for her owner. Thanks!