90 yj 2.5 engine change to 98 tj 2.5 FI

[freemancolorado]

I have a nice 90 yj with a worn out 2.5 TBI. I bought a 98 tj 2.5 FI that came with all the under hood wiring harness and computer. I was told that I need another wiring harness 98 tj (under dash) tough firewall to plug everything into to power up. What else would I need to do?
Is this right or do I need just one wiring cable from under the dash for key, fuel pump, and power to computer?
Please help or refer me to the right source. I need to get this started asap.
Thanks'
Old Veteran
303 674-0109

 

[Bounty__Hunter]

I would just use the '98 block and head.

If you're going to be messing with large amounts of wiring, may as well swap in a motor worth having, like a 4.3L or 5.3L.

 

[YJ GUY]

why not upgrade to a 4.0 outa a YJ ???

my 91 YJ 2.5 was getting tired so i bought a rotted out low kmi wrangler with a 4.0 auto and swipped the motor trans and trasfercase and wiring harness and comp. and the steering column with linkages and brackets because mine was a 5 speed and bought some new frame mtr mounts from the dealer mocked it all up welded them in and yea hah alittle time consuming but not to bad of a job.