M.Balmer

Anyone have experience swapping in a newer motor in their XJ? I just got a 91,4.0l, rough shape, and want to put a newer 4.0l in it. any thoughts? tips?

diskman

Bumpin for info too as my '92s 4.0 is whooped and I can get a really nice 98 4.0 with very low miles and all accessories for $400 fresh pull.

Throttle Jockey

you guys will be fine on the swaps. you will need to keep all the sensors and electronics from the original engine.(harness connections may differ from year to year) but i'm pretty sure its a straight swap.

jbetit

Throttle Jockey- M.Balmer has the renix. would that still work?

N20jeep

1991 is H.O, not renix

but renix will have its own set of problems if you're trying to swap an H.O. motor in.

jbetit

right. my bad, i looked below his avatar and it said 1990 lol. oops. just curious cause i have the renix

Throttle Jockey

still can be done. i have a 96 in my 90. some say you have to switch heads but you can do it with just manifold swaps. you will lose a bit of performance but i doubt you will notice it.

M.Balmer

oh crap i just realized in my thread i said 91. i have a 90. my bad. so its basically a straight forward i take it? i know ill have to go with the manifold on the newer motor, as well as exhaust. but im just worried on the electronics

troy fritz

Not all 91s are Renix.I have a bunch of XJs in my group and the early 91s are Renix and later are HO.Some of my buds have to order parts for a 90 when stuff breaks.If you have the closed cooling system then you have Renix if not then you have HO.