260E Wont run under load
 

I have an 87 260e 236K. Car was running very well with no issues. Parked at night and the next morning it was hard to start and less than a mile from the house started sputtering and would not run in gear. I changed the fuel filter as suggested and it was extremely difficult to start after the change. I finally got it to start and it will run all day at 1000 RPM or greater. If I let my foot off the pedal completely it will sputter and die. If I try to select R or D at any RPM it dies immediately. The fuel pump primes and then shuts off as it should, when the car is running it feels like the pump is running.

Fuel Pump - CPS - ?????

Any suggestions appreciated