Classic Jalopy

This is part three of a series where I am trying to diagnose poor cold starts on my 1979 280SE. Please click here for part 1 and here for part 2. In the last part, the fuel pressure tests had pointed to high control pressure. This would most likely be cause by the Warm Up Regulator (WUR). However, after a while the pump became very noisy, and since rebuilt WURs are expensive, I wanted to rule out a bad pump.

Luckily I had a 420SEL parts car on hand. The previous owner told me the fuel pumps were almost new. […]

I’ve been trying to get to the bottom of the running issues on my 1979 280SE. The last thing I tried was draining all the fuel and replacing the fuel filter and tank strainer. Once the car warmed up, it actually ran reasonably well. I took it for a drive for about 40 kilometers and it was running better and better. After this drive, I assumed that the running issues was due to bad fuel and that I had solved this part of the problem.

However, when I needed to start the car and move it out of the way […]