fuel pressure

What year?

That is right. If your fuel distributor. is original, then you need to replace your fuel filter first. Then I would replace your fuel pressure regulator. I am not sure on yours... on my old 380SE I had a needle on back of my fuel distributor... that has a big nut... whole needle unit comes out and has washers... these washers dictate the pressure level... but if yours is original, don't change the amount of washers... clean them out and replace.

It is possible you need to have the fuel distributor rebuilt.

I didnt realize that electronic fuel injected had a fuel distributor. Where is it located?

well, I'm guessing you're referring to the EHA (Electro Hydraulic Actuator) which is a little black box mounted onto and behind the intake. The EHA regulates fuel pressure and therefore amount

cheers

Fuel distributor is located under the air filter housing.

I believe the EHA didn't come until mid 80'ies (the "E" models), making the fuel injection "electronic".

Before it was just "direct fuel injection" (in contrary to carburator).

So, to 450sl:

The fuel pressure regulator provides a constant pressure input to the fuel distributor.

The fuel distributor then provides a pressure proportional to the air mass and distributes this pressure equally to all injectors.

Apparently the primary pressure is too low in your case. The cause could be:

- fuel filter clogging the fuel passage

- the fuel pressure regulator regulating to a wrong pressure

- the fuel pumps not being able to provide enough pressure

Since the fuel pressure is only half of the required, It could very well be one of the fuel pumps defective.

Guenter Scholz skrev:

I tested the fuell pressure before the pressure regulator and it is 0 should there be any pressure from the fuel pump? Its about 32 after the regulator. All plugs are fouling with black, so its definately over fueling.

That fuel pressure is too low... I'd suspect fuel distributor is bad and leaking internally.