Daniel.Lee
Member
I kinda doubt you'll see anything unusual on the fuel injector pulse with the scope though it'd be interesting. Should be nothing but a clean low frequency square wave. I'd next swap the #1 injector with one of the others and see if the misfire follows the #1 injector to the new location or if the misfire remains at the #1 location.
Early 97-98 4.0L engines had misfire problems caused by a bad (weak) set of valve springs the factory received. Replacing the springs was the fix for that. The same p/n valve springs are used, the bad valve springs were removed from the system.
Jerry,
I've already swapped injectors around to see if the misfire moved off of cylinder #1, and it didn't. So, I know my fuel injector is fine. I also tested the resistance of each injector and they all read around the same resistance.
Oh brother, valve springs? That sounds like it might be a painful DIY project. I'll have to do some research to see what I can do to confirm that it's a valve spring issue before jumping into replacing them. The misfire is sort of intermittent, which means that it can quite possibly be a weak valve spring that sometimes springs and sometimes doesn't.