CJW13

I have a 1974 merrcedes 240d. Up until a week ago it ran like a dream. This weekend i went out and started it and it instantly revved extremely high and I used the butterfly on the intake to slowly bring it down and choke it off. I tried again and the same thing happened. I found out that if I use the starter/shutoff knob and push it almost entirely back in i can bring the rpm down so to me that means its definitely getting too much fuel. So, that leads me to believe that the injector pump rack is stuck at full throttle. I also checked the vacuum governor and it does hold suction when the start/shut off lever is moved. I am out of ideas and need help. Thank you!