[ex_cel]

I have a 98 Windstar that runs poorly at idle and will stumble at higher speeds. Every once in a while, the car will not start, but if I retry the next day it will. I purchased an ELM327 OBD scanner to try and determine the cause even though error codes were not coming up. I noticed whenever I plugged the cable into the J1962 connector on the car(just the cable-no electronics), the car quit stumbling and every time I plugged the connector in when it would not start, it started with no problems. If I unplugged the cable immediately after a successful start and tried restarting, it would not start up. Any suggestions?