86 mercedes 300e fuel

[SIZE=3][B][FONT=arial][COLOR=crimson] I am replacing a 3.0 liter 6clinder engine in my friends MB.[SIZE=1] This is my first time with MBs, and I have both the tech manual and the "Owners Bible".
1. Fuel goes into the distribution center but nothing coming out the injectors.
2. What is the PSI rating for fuel system and how do I tell if a fuel regulator is bad?
3. How do I know if the ECM is screwed?
4. How do I test the PCU valve?

Any help would be much appreciated,

Ron's mechanic, MIKE

[stevebfl]

Fuel pressure shouuld be around 70-80psi (the later systems were higher but I think the 86 is in that range - it should be atleast that high).

The ECM only tunes the amount of fuel and it does its job by altering the leak rate of the EHA (electro hydraulic actuator). The system does real well when warm without the electronic correction and the answer is to unplug the eHA (black cube on the side of the fuel distributer) till you have the base setting adjusted.

Have you tried pushing down on the airflap to get fuel to flow. You may just have the basic mixture adjustment way off. I start from scratch by having a helper start the car while I vary the position of the airflow meter plate with my finger. This will get the motor running (all other things OK). I get the best mixture by varying my pressure on the plate. At the same time I turn the 3mm allen mixture adjustment with my other hand. If you are getting no fuel and the adjustment is the reason, pushing down the plate will get you fuel. Keep adding mixture with the 3mm turned clockwise until you don't have to help the air plate.

I neglected to mention the engine we are installing came from a '89 model year that was rear ended, not affecting the motor.
The motor we are replacing already is the second one installed... the owners kids worked those engines to death, otherwise the 86 is in excellent shape.

Mike