It was running fine,I parked it for about 3 hours,got in it to drive and it started running bad. The check engine lite came on, had it checked, the 3rd cylinder is misfiring.I replaced all 8 wires, and plugs. The coil packs are firing fine. This did not fix the problem. Could it be an injector?
my truck is running on 3 cylinders. on 1999 Mazda B2500
You seem to have ruled out all the ignition components, I would next verify the cylinder has compression equal to that of the other cylinders, make sure there is no manifold vacuum leak and then listen to the injector using the handle of a long screw driver held up tight to your ear and the blade of the screw driver tip on the injector you should hear it click when the engine is running. Compare the sound to a "healthy" injector.