Its either time to rebuild it or replace my motor. I've decided to get a new motor instead of rebuilding because mine has a lot of miles on it. I'm going to get a used 4.0l with lower miles. My jeep is a 1990 242 4.0l strait 6. I found a really good deal on a 1991 4.0l from a wrangler. The only issue is, i know that the computers are different from '90 to '91- and the new engine doesn't come with a computer. I was wondering is the thing still gonna run with the 91 motor or do i need to get a computer/wiring harness for the new motor as well.
thanks for all your help, it's gonna be my first engine swap and I need att the help i can get.

 

Just use the long block and reuse all your sensors and wiring.

 

alright, so your sayin just swap the long block onto the new engine and it should work? Whats gonna be involved in that as far as costs(new gaskets,etc) im tryin to do this swap as cheap as possible

 

allyou should need would be engine oil + filter, coolant, intake/exhaust manifold gasket,maybe a new tstat and gasket.
Good luck!

 

Alright thanks for all the info! Is there any info or pics on this that you know of i searched for about 2hrs last night couldnt really find anything. I'm just kinda nervous bout the whole swap its my daily driver and I wanna do it right and not have to mess around with it for weeks. I can do the thermostat , intake/ exhaust gaskets thats not gonna be a problem. Its more the sensors and stuff im not good with electronics i hesard thst the 91 doesnt have a knock sensor and the 90 does, so just wondering if that or any other stuff would be a problem