I have a 89 caravan with a 2.5 engine and it misses so bad some times it stalls. I have replaced the head (cracked), plugs, rotor, wires, timming belt, injector and took it to a garage that specializes in mopar. They couldn't find anything that would cause it. It started all at once and gets worse as time goes on. Any ideas other than the junk yard? it really is in good shape other than the miss.