Pvt.slaw

Just got my hands on my first Mustang. I picked it up cheap because the original owner thought the engine was bad. Still trying to figure it out myself. I want to preface this by saying I'm not that smart but my brother is a mechanic and I know how to Google lol. The engine is currently running on 6 of the 8 cylinders and my brother thinks it's a bad ecu but I'm trying to see if we might be overlooking something. We allready replaced the plugs, the wires dont look to be newer. One side of the drivers side coil is not firing. We replaced the coil and it ran beautifully all the way to the gas station and then like garbage all the way home. We tried switching coils again and the same side of the drivers side coil is still not firing. What were thinking is ecu or bad harness but haven't had any time between my jobs to get out and try and find any bad wiring. Anybody got any other suggestions on sumthing were overlooking?

dawson1112

My first guess would be a short someplace in the coil harness. I would start by looking at the plug that connects to the coil, make sure its not broken or corroded , and that it is seating in the coil properly. Then go from there.