Number 1: Old gas and CIS do not mix. All your problems will be residing within the fuel distributor and warm up regulator. More than likely, both the warm up regulator and fuel distributor are shot.

Number 2: You cannot do anything fuel related to one of these cars without the PROPER fuel pressure gauge. Want to fix the car right? Buy a pressure gauge designed to work on CIS and see what the pressure per the Mercedes manual. CIS cars have varying pressures dependent upon ambient temperature.

Number 3: Be more precise with your wording and someone may help you. Try some diagnostics. The car is trying to talk to you. Listen to it and then post on here in such a way that we can understand it.

Good luck on your project!

Aaron