To All who may have an idea what I should do next, please respond. On a cold start, my 89 240DL will start but run very rough and will continually quit in idle. The only way to keep it running is to keep the pedal down. After warming up, it runs smooth and has no problems at all remaining in idle. However, after warming up it does idle higher than normal. Here is what I have done so far: checked all vacuum hoses (look good), opened and cleaned the throttle body with carb spray. My Haynes manual says the coolant temp sensor may be the problem. Haven't changed that yet. Any other ideas? Thanks!!