1990 Trooper has no spark

This all started about a week ago. After sitting over night it took forever to get started. Now, I have no spark at all. I have changed the coil, wires and distributor from a working 1990 trooper but still have no spark at all. I also have power to the coil. The engine IS A 2.6 4 cylinder. What should I try next. Thanks

Scott

Latest on the Troop. Today, changed the power transistor and the ECM, still no spark from the coil. Tried another coil, same thing. Did notice one thing, when I first turn the switch on, I get 1 spark from the coil, no more. Is there anything in the switch itself that would cause this type of problem?

Scott:banghead:

Latest on the Troop. Today, changed the power transistor and the ECM, still no spark from the coil. Tried another coil, same thing. Did notice one thing, when I first turn the switch on, I get 1 spark from the coil, no more. Is there anything in the switch itself that would cause this type of problem?

Scott:banghead:
Did you get this problem solved? I have the exact same problem, W.

update: check that the wire from the fusable link box to the main relay is good. Run a bypass if nessesary. They often break and will cause the problem you have.