I have two trucks. One is a 1985 five speed 4x4, one is a 1986 auto 4x4.I put the 85 engine in the 86 auto truck and swapped out the flywheel/ clutch so the auto would bolt up, the 85 ran fine before the swap , ran really really good, no misses at all. Now that it is all installed in the truck with the auto the # 4 cylinder is no working. The wiring harness is the one for the auto truck.
If I pull the #4 sparkplug wire there is no change in the way the engine runsIt has fire, If I pull any other wire the truck almost dies cause it's trying to run on two cylinders.Changed the spark plug no change. I even swapped out the #4 injector on recommendation of a mechanic thinking when we pulled the engine trash in the fuel rail fell and stopped up the #4 injector. Still no change in the engine running with a miss. I disconnected the wires going to the #4 injector no change . Disconnected the wires going to the #1 injector and the truck almost dies.
Any ideas what is wrong with #4 cylinder?