Is there any difference between a YJ and XJ pump, anything that would make the motor run different? Swapped in a YJ tank in the back and running stock in-tank pump
if the yj had the same size engine as the xj...it should work fine. but if the yj had a 4banger in it and the xj is a 4.0 it will idle fine but die out when you get on the gas hard. I don't know if they are interchangeable or not though.