More research on this, this morning says that there should be 72-86psi at idle. This is a very wide range! After the welding is done on the fuel rail this morning, installation of the external fuel pressure regulator, return line, and "straight through" style fuel filter will begin. It shouldn't be too difficult since the fuel rails are already setup with the fuel rail loop fittings, and the actual return line is already in the car.

The big question is how the OEM setup regulated pressure. I am reading conflicting information on the subject. Later cars seemed to have gone to dual in tank pumps with a regulator. Earlier cars had a fuel system setup more akin to the Crossfire, but the actual pressure regulator appears to not be there, ie, the pump ran wide open to the engine, without regulation. It is amazing to me how little true technical data is out there for the MB cars. It's as if the whole setup is a mystery, and people are just used to operating in the dark. This is the only series of cars I have worked on where hard data seems to be so elusive. I digress.

Off to the shop, while it is still cool out.