Okay, I haven't been here for awhile. Fortunately, only minor problems. Unfortunately, other people ask "smart" (?) guys for help, who in turn know when to and who to ask for help. My brother has a '97 F150 SC, 4.6L, probably 4R70, and ~180K. Usually runs fine. He's a military mechanic and works on big Hummers and aircraft etc. His e-mail is out (and I have problems at the dial-up ISP level-it's late) and he lives 300 miles away. Best I can tell (by phone) is that his truck runs fine in Park and neutral but in Drive, it idles too low or stalls. I asked if he could run codes. No engine light is on. He said he could accelerate and get the truck to move in Reverse but couldn't go forward to get to a shop. He may have a friend who could run diagnostics in the driveway. I'm not real familiar with this truck. I thought about vacuum leak, or TP, or torque convertor clutch switch (CCC-convertor clutch control solenoid) but I don't know where to look or to advise. I tried a search but only a quickie. I'll talk to him again by phone tomorrow or rather tonight, now. Maybe someone has experienced or heard of similar problem/symptom and can point me in the right direction. I have the Ford service cd-rom but it's not much use for diagnostics without codes. Truck was running fine last weekend because he drove here and back. Wouldn't think it would be trans. related either. Possibly IAC or similar? Hopefully, this is enough info., if not I'll try better later. I haven't been able to stay connected very long tonight. Thanks for any insight/assistance, Tim