Need help 84 500SEL
 

So I picked up an 84 500 SEL German grey market car. Very nice shape but has a couple issues. So when I try to start it, it hasitates and dies, you have to push the accel down a little bit and it will start. It then idles rough. Sitting in park once it warms up you can rev it up and it smooths out. When you put it in gear you can punch it and it does hardly move and blows a good amount of black smoke. I can tell there is a few vaccum leaks.
Anything else I should be looking at?
Thanks
Cheers
-Cary

Difference in fuel pressure is how a CIS car operates.

I would start by watching the control pressure VS the system pressure.

Ok so I have been trying to figure this car out.
I found out today that when you start it up cold, and pull the plug out of the Frequency Valve that it runs alot nicer and smooths out and does blow a bunch of black smoke on Accel. But once it gets around 80*C it won't idle with Frequency Valve unplugged??

Well heres the update yall. I fixed the problem. Turns out this car never had a Frequency valve. The one on my car was added on. So I unplugged it and tuned the car for not having it.
Runs amazing!!! I have been driving it all day! Wow.
What a Fantastic car!
Thanks for any input.

Cheers
-Cary