Like everyone else, I suggest fixing the timing problem. If you still have issues, try disconnecting the battery and then disconnecting the wiring bundle that contains the engine management wires (the one closest to the passenger side firewall on my truck) and check for water intrusion. I had this same problem last week and when I went to chase wires for continuity, I found the PCM connector was full of water (after spending a couple of hundred on parts). Also, faulty grounds may cause this type of problem. Remove and clean all grounds between the engine and the chassis. Last, before getting into spending money on parts that may be unnecessary, get a multimeter and check continuity from the PCM connectors to the sensors. Good luck, I hope my experience helps.