2000 tj with a 4.0, only 58k miles, ive always taken care of it, doing oil changes when needed and spark plugs etc. it was running perfectly fine i went to the store and back, parked it in the garage but the next day it wouldn't start. it would crank and want to start but backfire and pop, this was about a year ago ive had it sitting since so i don't remember exactly which order i did this, but i replaced all the sensors with brand new ones, it had fuel pressure and compression, i even changed out the sensors again with ones from an old 4.0 i had but no luck, i swapped my ecu with my dads 2000 tj but still no luck any idea on what it could be?
