Mercedes Forum Thread

I bought a 1986 300 E with 155K miles on it from a deceased lady who lived outside of Palm Springs, CA. The car had not been used since 2017. It was stored under a lean two and in fairly good condition. It did not run. I had it shipped to southwest Oregon for $1100 in 2019. I have been messing with it since. I always wanted to work on one of these. I discovered the fuel pump was dead. I bought one from an estate sale in Florida. It was new and a factory pump. It was dead! I cut it open on my lathe and found that one of the brushes was not in contact with the commutator. I bought and after market fuel pump. I bench tested it and it worked. I installed it; but I still had no flow to the injectors. AFter a lot of chasing my tail scenes I discovered that the polarity markings on the fuel pump did not agree with the factory wiring. In other words, the factory had put ring terminals on the wiring to their pump that were the opposite of the after market pump. So I was running the pump in reverse. No fuel to the engine. In the course of this I burned up the fuel pump relay.

It takes time to recover from these bozo moves. But I persevered and it is now working. I am onto to fining tuning the beast.

So be aware of subtle differences. Had I tested the polarity of the factory wiring this would not have occured.