ModE211

Hello changed the fuel pumps and sending unit on my 2003 e55 amg, tried installing the fuel pump adapter but the car does not start with adapter installed, the pumps have the part number that requires the adapter. So I am wondering how to fix this? Maybe requires ecu tuning the pumps prime with and without adapter.

E55Greasemonkey

Follow the wires (before installing the pumps) to make sure both red and both brown wires line up from the pumps to the body wiring harness. It's quite simple.

ModE211

that’s where I messed up and I don’t want to pull the top off the pumps; and it runs without the adapter so no adapter it is. Worst that can happen is they blow up, I’ll see if I’m going to cut out wot if so I’ll pull it apart. Thanks for the reply.

E55Greasemonkey

Worse that can happen is your engine blows up from running lean. You only need to remove the fuel pump ring and lift the hat slightly to see the wire colors.

ModE211

yah I will be doing that... not going to risk it. I’m super indecisive, gonna lift it up and see how the wiring is, make sure both pumps are getting power and ground correct?

E55Greasemonkey

Follow the wires from the pumps to the 4 pin connector. Each side of 2 pins is one pump. For example you can have each pump's positive wire at position 1 and 4 on the 4 pin connector with both grounds in the middle, or a staggered setup...
+- +-
+- -+
-+ +-

Remove the adapter harness and plug it into itself. Then you'll see it's only purpose is to change polarity to one or both pumps.

I didn't use the harness on mine. I just de-pinned and moved the body harness wires to match the new pumps, but you need a special tool and a delicate touch.

Red is postive and Brown is ground. Make sure everything matches up.

ModE211

alright thanks a lot will do that asap. Do you know the symptoms of a bad cylinder on the m113k

E55Greasemonkey

Misfire, rough idle, oil fouled spark plug...no different than other engines. Compression test will confirm followed by a borescope inspection.