correction the piece i replaced was called a potentiometer, its the black box on the side of the airflow meter.
Would die coming to a stop, would die turning, would stumble and die while accelerating, it pretty much would die while driving.
When the car was out of gear it would run fine (less the rough idle), but in gear it would quit at weird times.
Read on the board that the OVP can cause this problem, so i opened it up, everything looked ok, put it back in the car and the same things started to happen.
Had a check engine light on, pulled codes 7, 10, 27, RPM signal, and CIS-e and EZL faults. Removed the flywheel sensor, found it rather gumbed up, cleaned the sensor and replaced. Cleaned the TDC sensor on the front of motor.
Pulled MAS relay, opened it up and checked for any damage, there was none (MAS contains the fuel relay on the 1990 300e's), replaced MAS.
Thinking that the OVP might actually be bad, I pulled it, and ran the car without it, had the same stalling characteritics, replaced OVP.
Thought for a while, thought it might be fuel pumps, removed MAS relay, jumped 1-2 pin, checked to make sure both pumps where pumping, they where, replaced MAS relay.
Thought for a while longer, asked myself what could be causing this, then I realized under load the fuel pumps would be drawing more current, if the alternator couldn't supply enough it would shut it down as a power fault (this might be completed wrong, but its the why it went over in my head).
Pulled voltage regulator, it was next to nothing. Installed new regulator, car runs nice and smooth now, doesn't die.
Currently no codes are getting thrown out.