Snap some photos of the injection pump side of the engine....

Something is most likely up with the linkages.....the 77 used a completely different set up for linkages then the post 80s.....1980 year w123 used some very strange and rare linkage parts....

I would also assume the vacuum line for the shut off isn't connected...

The 77 also used a different vacuum pump setup then the 80....it used a diaghram pump which are known to tare and the 80s used a piston pump...

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