Question about 1991 Mercedes-Benz 420
I had this problem. It turned out to be the "fuel pump relay control unit". It is situated with two other box shaped units and is the largest of the three near, or behind the battery. I opened the unit up and on "very" close inspection found a bad contact on the enclosed circuit board, I gave the connection a clean and added the maximum amount of solder (weld) to dissipate the heat. It was great to hear the pumps running possitively again and of coarse the problem was solved.
Posted on Nov 26, 2008
I have a 1990 420sel that did the same thing i changed the ignition coil been running every since
Posted on Aug 18, 2008
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Posted on Jan 02, 2017
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