Can anyone tell me what the switchover valve does? According to my Haynes manual it is in the line known as Aneroid compensator delivery. Sounds like something out of Star wars to me. I am trying to determine if it is necessary because the 84 300D motor seems to run fine with the hose connections pluged and this part removed. thanks.

1984 300d Turbo
It Is A Safe Device To Turn Off The Press To The Added Fuel To The
Injector Pump Gets Its Pressure From The Intake Rear Take The 12 Mm Off And Clean The Line You Will Have More Power At 2ooo-4000
Rpm Another Safe Device Is In The Turbo Over Press Easy Diy

thanks for your response about the switch over valve. I think I understand what you are saying but I do not have the valve lines so I can only go by what the pictures in my Haynes manual show. In the manual it appears to be a valve with two hoses running to it but when I try to buy this valve auto parts stores show it with three hoses and a electrical connection. Does anyone have an extra of this valve they would be willing to sell? More info on the valve itself would be appreciated. Also I do not have a clue about what you said regarding the "Turbo Over Press Easy Diy"

thanks