I moved the #5 injector to #4cyl put in the 88 ecm ran the truck for about 10 min,Then it quit.Opened the ecm,found where it blew,in a different location.I pulled the injectors and ohmed them all,5 were at 12.3,0ne was reading O.That was the one on the #4cyl.I traced every wire in the engine bay and came up with nothing.Changed back to the old injectors after ohms check they all read 12.7. Put another 90year model ECM in.Ran the truck for 1300 miles on vacation and it continues to run today.