next to battery the are some plugs that can be moved specially if you disconected the Battery look for loose plugs especially the bottom one cam and crank shaft and position sensor signals can be lost it the bottom conector is loose. if connector looks ok. test the cam shaft sensor. if van runs fine at idel and on flat surface but only up hill is the problem the fireing order is out of timing if sensor is sending wrong info due to a sensor malfuntion or loose conector hope this helps. i had cam and crank shaft position sensor problems that got solved by replacing both of them and tide that loose conector. on my 98 caravan 3.8l