2000 Ford E-150 Cargo van V-6, Automatic, w/air. Idles fine in park and netural. Dives fine in drive and reverse. When van comes to a complete stop while in drive; van pulses or surges forward then stops and repeats these surges until driving again. Noticed one other thing abnormal. Van stalled when just while getting on my way out in morning. (Van never stalled once in four years) also has not stalled again since that one time. It's best described as rocking forward and backward sometimes more or less, About 2 1/2 years ago (12,000 miles ago) I had the trans filter and and fluid changed. I climbed under the van and noticed a leak in the very bottom of trans. The area that has a small leak looks similar to a freeze out plug from an engine blockhttp://images.intellitxt.com/ast/adTypes/mag-glass_10x10.gif (http://www.automotiveforums.com/vbulletin/showthread.php?t=940772#). I checked trans fluid, by the dip stick on level ground in park running at reg. temp level is fine. It started happening at once. Sometimes van will come to a stop and not surge. Maybe 1 in 15 times. Times are tough! I hope I can tackle this on my own needing a tranny will break my back right now. Please advise. Thanks:banghead:
Van has 114,000 miles and never tows.

Auto Zone and Advanced Auto will scan the engine free. It appears more of a running problem than a transmission. Try this and post what codes are showing up at this time. Ammco transmission scans free in the Atlanta Ga. area. You are free to accept or reject their job quote. If they get 50% they are making money from the free code check don't feel bad if you reject their offer.

We used to have that feeling on an 89 Buick Century. It was the lock-up toque converter that would sometimes not fully release, due to a problem in the solenoid in the valve body. Quick cure was to disconnect the plug that made the torque converter lock-up. But I dont think you can do that on a 2000 Ford, since then the tranny would not work much, if at all.

It also sounds to me like a torque converter lock up. I'm not even close to a pro, but that would be the first thing I'd suspect. From what I've read about transmissions, it would be okay to disconnect the torque converter lockup clutch to see if that cures the issue. you can even run the transmission that way but at reduced fuel economy at speeds of around 40MPH and up (when the lockup clutch would normally engage).