from 91-88 xj

[stace]

Well I bought a 91 xj for a project but the deeper in. the worse it turned out to be > So I have found a great solid 88 i6 how different are they in wiring computer

 

[88xjlover]

The 91 is HO Chrysler fuel injection and the 88 is Renix. Do a search on here about swapping but if the 88 is running well then it's alot easier to leave it alone. You won't get any HP gains unless you swap entire motor. You really can't mix and match mutch, either.
Good luck!