Here's what I'm working with, I have a 90 Yj. The guy I bought it from pulled the 4.2 and dropped in a 4.0 from a 98 Xj. Well he didn't want to or didn't know how to hook up the fuel inj. So he put the 4.2 head and intake on the motor. Well as you know this is a Sh#$y setup. Don't get me wrong it seems to run alright but I get about 10miles a gallon and I know I'm missing some power. So I have the 4.0 head and injection system that I'm going to put on but I need some help with wiring. Does anyone have a wiring diagram and some advice, or even better if someone has the time and lives in Jersey I'll buy the Beer

What year and vehicle did the computer and wiring and head and all that come out of?

You'll also have to put a new fuel pump in. What trans are you running? WTF? Does this thing just think it has EFI? Did he install all the rest of the sensors? EFI needs the CPS that is bolted into the trans bell housing, knock, MAP, IAT etc...

Everything is out of the 98xj that the motor came out of.I don't think this guy didn't hook up any sensors. I have the Comp, wiring harness, elec fuel pump, throttle body, I think everything from the 98). I'm running an ax15 trans.

Go get a chilton's book for the donor for starters. In the book will have a complete wiring schematic of the engine control system.

I have already gone to my wiring schematic on my engine many times when installing custom stuff!(93 YJ 4.0 turbo charged)

Sheet 1 (http://www.timstrader.com/web/tech/98-zj-engine-performance-1.pdf)

Sheet 2 (http://www.timstrader.com/web/tech/98-zj-engine-performance-2.pdf)

Sheet 3 (http://www.timstrader.com/web/tech/98-zj-engine-performance-3.pdf)