I recently purchased a 1986 560 SL that have been stored in a heated garage for the last 19 years. The paint and interior are nearly perfect and the wife is slobbering, wanting to get her hands on the car. The problem is reliability. I removed the fuel tank and cleaned it out blew out the fuel lines replaced fuel pumps and filter as well as the screen. New battery and tires and the car started right up and ran like a striped assed ape! For a couple weeks I took it on short trips 30 minutes or less and it ran perfect. My confidence built up and I took it on the longer trip and it suddenly died at 50 minutes. It re-started and ran perfect for 20 more minutes died suddenly again, restarted and ran the rest of the way home, about 20 more minutes. I did some reading on these forums, and replaced the fuel pump relay. On the next drive it died at 50 minutes again, started right back up and ran perfect the rest of the way home. I parked it in the garage and have been on a one-month bike trip, just got back yesterday, decided to drive the car in to town for groceries. 15 minutes to town. It made it to the store running perfectly, when I started the car to go back home it was missing badly, black smoke out the exhaust and the economy gauge would peg itself to the right side anytime I stepped on the throttle. Grossly over rich. Barely made it home. I have ordered new spark plugs and wires. The car does not have the OBD port. Just the 9 pin circular port for the oscilloscope. I believe I have 2 separate issues. I know there is a ton of knowledge on this site. Does this scenario sound familiar to anyone out there? Thanks in advance for any direction. Would love to let the wife drive this beauty!