Has happened to my 103 twice now. Just shuts off and dies but I can get it into neutral and do a quick restart. What I found was I was running too lean on air/fuel mixture. However, it could be the fuel pump relay as well. Wiggle it around a little. Do you hear the fuel pumps when you turn the key? Your CPS is right behind the fan on the bottom on the base of the engine. See if its wet or covered in gunk. Cleaned my daughter's off during a water pump change and it starts first crank now every time...don't know why though. Mine doesn't and it's 4 years newer with less mileage. Best of luck.