We were trying to start a 1990 Jeep Cherokee with a 4.0 last night. We put a new coil, and new module and we still have no spark. There is fuel in the lines and the rotor turns, so the timing chain is good. It does have a short somewhere, because he has to keep charging the battery. Any suggestions on what else to check. I'm thinking it might be the Computer. But if the computer is bad would the fuel pump still turn on when the key is turned. How can we check the computer.