Vintage Cars: 1960 Mercedes 300, vacuum leaks, mercedes 300

Question
I have a in-line 6, gas fuel injected 1960 Mercedes and it cranks and starts but is not smooth.  We have cleaned the injectors, and to no avail it still runs the same.  Any suggestions?

Answer
Could use a little more info, How did you clean injectors?
Are they all working?
How many miles, general condition of engine?
What do plugs look like
Points /Dwell - Set?
Vacuum leaks?
Does it have power under load
Gas filters clean
Fuel _ water ? old?
more iformation will allow me to help you more
Happy Motoring
Ron