I have a 91 b2600i 4x4 and i cannot get spark at the plugs. i have replaced the cap rotor wires and distributor, igniter testsok, the coil is good, and the voltage from the ECU reads right. I'm pulling my hair out with this truck! The distributor is a remanufactured one from Autozone could i maybe have gotten a bad one? its happened to me before from them. Is there some other component that would stop the distributor from firing? I REALLY need help on this one. Thanks in advance