When cold, starts easily and immediately dies

1988 T'Bird, 3.8L. When cold, starts easily and immediately dies. Repeat 4 or 5 times, stays running but very rough idle. Wild (1-2000 RPM) fluctuations. Put it in gear, stalls. Repeat until finally under way. engine missing dramatically accompanied by wild fluctuations in RPMs. Top speed of maybe 50-55 MPH. Stop at red light, low swing of RPM fluctuation- dies. Starts right up, shift into neutral, feather the gas pedal to keep it running, light turns green drop into gear and sputter away. Problem came on rather suddenly. So far I have replaced dist cap and rotor and added injector cleaner to gas to no avail. Plugs and wires are suspect but it ran sweet right up 'til now.

Response:
The first step is to extract any check engine light codes. This can be done free and here is how to do it: Ford Trouble Codes

Once you have the codes, it may guide you to your issue. There are many things that can make this problem happen. A failing MAF Sensor, Vacuum leak, If you notice smoke.. an injector could be stuck open and giving the o2sensors false readings... the good news is that it restarts.....