Have a 90 xj 4.0 has all new vac hoses I put a k/n cone type filter new fuel pump and wix fuel filter new plugs wires cap rotor and it still has a little hesitation when I hit the gas. Mabe injectors ? Anybody have this problem I have a 92 HO that does not do it.

 

Maybe o2 sensor, could be injectors, map, lots of stuff.

 

I forgot about o2 I did swap map with another to test no diff I'll try o2 thanks for input