4.0 engine back fireing

I have a 4.0 engine that is in a 93 yj ya i no its not a xj but its a 4.0 it has 112,xxx mi on it and the problem is when you punch the gas it seems to hesitate and some times it will back fire through the intake.i have another 4.0 engine so i have swaped over some parts. hears is was i have done so far.

TPS. sencer my jeep eats thease things all the time it is not this
idel air speed sencer.
distributor.this was replaced because it was sucking up oil and no help
cap,rotor,wires.
checked compression was well with in speck.
cleaned throttle body.
indexed distribtor.
i tested the fuel pressure 30 with regulator 39 with out however upon bringing the RPMs up and letting of the gas the pressure would drop to about 27
and last it has no blink codes at all and i no i am trying to get em the right way because i have done it on diferent jeeps help thanks wes

Double check that the spark plug wires are connected properly (1 to 1, 2 to 2, etc).

ya thay are for shore

Is it when you got your foot in it/ like it running out of fuel or getting a lean fuel condition?

How about you fuel filter.

it is a lean like condition and i just did a fuel filter last weekend

im thinking either a ecu or a fuel pump?

any one?

I have the exact same complaint, feels like someones turning the fuel off, my plugs come out white as well as the oxygen sensor, I have done nothing but dump money into this thing to try and correct it. I have replaced o2 sensor, IAC, plugs wires,cap,rotor, fuel pump,fuel injectors, pressure regulator,swapped throttle bodies,coolant temp sensor,intake air temp sensor, map sensor to no avail, still runs lean and intermittently backfires like its running out of gas. Is yours an Intermittent problem??Possibly burnt or damaged valves?maybe?

my plugs look ok