rough idle, very hard start 240

[mercedes]

I am working on a 1989 240 with 202,000 miles. When starting the vehicle, its fires right up. After 2 or 3 seconds, when coming off of high idle, its will start to miss and buck severely, and will not keep running. While giving it throttle, to keep it running, it will sound like it is out of time.
Backfiring, stumbling etc, like a faulty air mass or a stuck egr. I have checked the cam timing, and it is ok. The codes that come up are 1-2-1 and 1-1-3. The air mass readings on the pins have checked out ok. I have installed a known good air mass, and it still runs the same. When disconnecting the air mass, the vehicle still runs bad. I dont see any vacume leaks at this time, or air getting past the air mass. Fuses are good also. I havent checked the fuel pressure yet, my guage doesnt adapt to this system, but I am going to get the tools today and check. Can a faulty fufel pressure regulator cause this condition?. The inside of the vacume port on the regulator smells of fuel. Pleas help any way you can.
Thankyou

[wojeepster]

Yes a bad fuel pressure regulator will make the car run bad. The faulty one I replaced made the fuel pressure too high and the car ran very rich. black sooty exhaust, etc You should not smell fuel on the vacuum line.

121 air mass sensor
113 max enrichment sensed heated o2 sensor