John, the list of possibilities is still pretty long. If you are mechanically-inclined, you should begin by getting the factory service manual CD for that car (they're available from MBUSA or maybe even from other forum members), a multimeter and Mityvac. Then, you're going to have to systematically diagnose the fuel system (pressure and volume at the fuel distributor/injectors) and the electrical system (ignition, relays, sensors) to rule out specific causes and components. If you are not up to that sort of stuff and you don't have a friend who can help, you'll need to take it to an independent garage specializing in MBz. You could easily spend more getting it to run correctly than you paid for the car. The possibilities still include almost everything on my earlier list, plus fuel pumps and a fuel accumulator. You can do some things right now that will be helpful:
1) Your CEL is on, can you read the stored trouble codes? If it's a California version car, there is a small, black plastic diagnostic box next to the battery where codes can be checked;
2) Check the fuse on top of the OVP (located against the firewall behind the battery on the passenger side)
3) Check all of the fuses in the main fuse/relay box (located near the firewall next to the brake booster on the driver side) and spin each fuse in its holder
4) Pull about 3 spark plugs and check the condition of the electrode tips. Are they wet? Oily? Black with carbon deposits? Or are they dry and tan?
Post back results and you'll get plenty of advice from members. Good luck.

__________________
1988 California version 260E (W124)
Anthracite Grey/Palomino
Owned since new and still going strong and smooth
MBCA member

Past Mercedes-Benz:
1986 190E Baby Benz
1967 230 Inherited from mom when she downsized
1959 220S Introduced me to the joys of keepin' 'em goin'

There are only 10 kinds of people in the world--those who understand binary and those who don't