Hey guys, so I have been in the process of swapping the engine in my '81 300D with a '79 300SD's engine. I'll try to keep this short and sweet. When I went to bench test the engine before throwing it all back in, it started right up and revved to full throttle. I did not have the throttle engaged and my IP timing was set before I received the engine so my friend had to rip the fuel lines off to get it to quit.

Fast forward to the engine being in my car, It started to rev itself up again on initial start up. I realized I didn't have the brown/blue vacuum line hooked up to the vacuum port on the back on my injection pump, so I'm hoping that thats the reason to this very terrifying problem. I really don't want my shiny new engine to throw a rod or blow up, plus I never realized how loud they can get at 5000 rpms. My neighbors weren't to happy either.

Any advice would be greatly appreciated! If I need to provide any more info Ill be happy to do so.

*Ive checked the throttle linkage 10x over