broken/ corroded wire in the harness. you need to check the powers at the relay. there is a wire that branchs off and goes to a few different components, that connection gets corroded and you loose power to a few different relays and computer. you need to do power and ground checks before throwing more parts at it. relay should have 1 power wire all time and 1 with key on. the computer controls the ground. It has been a while, If I remember correctly the branch is in the harness between the fire wall and battery along the left side inner fender. look for the green powder(corrosion).won't be easy to spot, it is inside the taped harness. Getting an aftermarket Bad part is not that uncommon. a scan tool that is bidirectional can command the coil to fire/spark. if that happens then the wiring is good,