Since the fuel system sounds good, I would tend to lean more toward the Idle Speed Control Valve (slide valve) and/or the Idle Speed Control Unit. When mine went bad, the car ran fine at highway speeds, but pull up to a stop sign/light and it would die.

Also, awhle back I was swapping out the control unit just to see if mine was bad. I put a bad one in and revved the engine. After letting up on the accelerator it died immediately.

If you are unaware of the locations, the slide valve is silver and on the front top of the engine. It sets between the distributor and Warm Up Regulator (if you have the latter) and has two wires going into the front of it. The control unit is under the dash and probably behind the glove box liner.

__________________
Don
'85 500SL (Euro) - 186,000 w/a complete restoration and engine rebuild at 154,000
'95 C280 - 174,000