Expert Advice Needed: My '87 240 (B230F) always starts right up. When the car is cold, (not driven for more than a few hours) it will die every time I put it in reverse or drive. The car starts right up again and when I put it in gear, it's fine and I can drive away. If I rev the engine a little bit when it's cold or let it idle for more than a minute, the chances of the engine dying decrease.

The condition has worsened over the last few months and the car sometimes feels like it is going to stall when braking for a stop light. The rpms will drop, the engine kind of chugs a bit and I can feel the computer kicking in to prevent the car from stalling. It is so noticeable that when I brake, I feel the engine fighting back against my braking.

Here's what's been done over the past 6 months:
New plugs, wires, O2 sensor, fuel filter
Cleaned throttle body, flame trap, vacuum lines checked

Any ideas?

Chris '87 245 (241K)