lowpost99
Lowpost99
Can you mix these? My 2001 5.3 NBS ignition coils aren't all the same. #1 cylinder has a round coil and all of the remaining coils are square. I discovered this while chasing down a misfire that I apparently created. I removed both coil harnesses to test the coils, and I don't remember if that one round coil was in the #8 or #1 position, but now it's in #1. I may swap them to see if my misfire goes away. The big picture was I was chasing down a high-speed misfire and testing the coils was just a step in the process. I also cleaned my EGR valve, and soaked my O2 sensors in gas overnight. This morning I've got misfires at idle and checked all the coil wires and plugs and everything seems tight. I read about some people swapping between round and square coils, but nothing about mixing them. My engine was swapped several years ago and I wonder if the guy just grabbed what ever was around. Also should I disconnect the battery and let the PCM relearn the position of that one round coil? I also wonder now if the mixture of the coils could in fact be the cause of the high-speed misfires or what some are saying is less stability in the square coils under higher stress, and a more consistent spark from the round ones?
