91 cherokee 4.0 swap

[Rockjunky317]

i just picked up a project cherokee and the guy swapped a 88 engine into a 91 cherokee, and now it only sputters kinda seems like a crank positioning sensor, they gave me the flywheel off the 91 to see if that might be the problem, im wondering if maybe the computer needs to be swapped to a 88 computer? all lines and connections seem to be hooked up correctly, any suggestions

 

[Badger]

I don't see why you would swap an 88 into a 91. Thats a downgrade not an upgrade. As for using an 88 computer. Not going to happen. The 88 would be a Renix system while the 91 is OBDI. Completely different wiring harnesses. Honestly I would yank the 88 and try to find a newer motor from a 91+

 

[mattvw65]

Yes the flex plates are diffrent. the early renix ones have twice as many holes in it for the Cps pickup. change the flex plate and it should be good.

 

[Rockjunky317]

ok i will change the flex plate, as to why they swapped out the 91 for an 88 i have no idea why, they kept the 91 intake manifold

 

[Rockjunky317]

so if i were to get a new engine 91+ should work i can get one at pick n pull for about 200

 

[iamsparticus]

i say go with the 91+ 100% higher out put and no closed loop cooling problems

 

[Badger]

i say go with the 91+ 100% higher out put and no closed loop cooling problems

Huh. the cooling system of 88 wasn't swapped.

 

[Rockjunky317]

doesnt look like it but im not sure i havent payed to much attention to that