Rough Idle, 1984 300SD

[Lampbum2]

Hello,
I am trying to get my motor to idle smooth @ 800 RPM's, at 900 and lower the car wobbles, now idles around 950 on the tach..... 305,000 on the motor, things I have done, below.

A). Adjusted valves to the loose side.
B). Changed injectors out of the parts car, into the 1984.( It idles smooth )
C). Air and fuel filters, bypass hoses, ( no air in the lines, that looks good )

The only thing I can think of next is the compression test? The fuel pump is a maybe, but I do not have gauges to check it, but I do have another pump that was put on the parts car, brand new Bosch with very low miles.

Anyway, any advise, ideas that would be helpful?

Thank You ahead of time,
Jim