90xjtim

I'm new to the whole jeep community. but i have two xj's a 94 with a rusted out body and suspension but low miles motor and tranny, transfer. and a 90 with good suspsension and body but 260,000 miles. I am plannin on swapping the 94 motor to the 90 ive heard that the injection changed in 91 so i was going to just swap the block and leave the intake/injection system in the 90 intact. just wondering if there is a whole lot more to this than what it appears. any help would be great.

BlueXJ

You can swap the motor but you need to retain the head,intake and exhaust from your 90(Renix) as the electronics are not compatible with the HO from the 94. With some fab skills you can swap the Renix throttle body to the new intake and retain the head intake and exhaust but it is very complicated to swap throttle bodies electronically.

Abovetimberline

Recently I put a 91 in my 89,same swap as you are doing,there is two ways you can go,either put the 94 in your as is along with the control system from the 94 or use the long block from the 94,if you decide to use the long block it will work just fine,I just removed the intake and exhaust,distributor,flexplate,and used everything from the 89,in 91 the control system change from the renix to the chrysler system. I am using the new head from the 91. what you gain from the h.o in my opinion is not werth the effort of changing the control system over,here in ca when you make major changes to your engine away from orginal you have to have them refereed and it is a pain.

90xjtim

Thanks, I don't know what I was thinking but I forgot that I would have to keep the renix head. This may be a total newbie question but what is the HO?