[mmcarguy]

Hey,

Just bought an 84 CJ7 Project....The 4.2L motor is out of the jeep and I was just thinking of finding a 4.0L (93-99) instead of getting the 4.2 rebuilt. I searched and searched the internet on the CJ 4.0L swap, but it seems there isn't too much detailed info out there. Also, I am looking for a yj tub to replace the rusted out cj tub, etc (probably just end up getting from junk yard or classifieds). Any help or direction would be greatly appreciated.

Thanks,

Matt

[gojeepin]

The engine itself is a direct bolt in... what else are you looking for? I carbureted mine but you can use the fuel injection it comes with.

[supraman1990]

check the sticky thread at the top. Their is a whole thread I made about the swap. Also, if you have specific questions, feel free to PM me.

[mmcarguy]

I guess what I'm looking for is more info on the wiring...I know the block bolts in with the cj motor mounts...but what is the best 4.0L to use (93-95 OBD I or 96-2001 OBD II). I need to upgrade the fuel tank and fuel lines for the increased fuel pressure. I would like to find more detailed info on how to wire the motor with the computer (use a wiring harness from the donor?), etc, because i'd like to utilize fuel injection.

Thanks for the help,

Matt

[Happy Joe]

I used the stock harness and cut away the parts that I didn't like. Depending on the year of the 4.0, and the transmission used the crank sensor (if equipped) may need a bit of thought.
I was very disappointed in the 4.0 performance after installation (once the joy of fuel injection and new engine wore off) but the fuel injection's lack of issues off road makes this a good swap just by itself, IMO.

The stock tank and fuel lines are fine.
After lots of fussing around with fuel issues I settled on a high volume low pressure electric pump near the tank which then feeds a high pressure pump in the engine compartment. This system has been trouble free on my CJ-7 for the last 8-10 years, and is the same that I use on injected V-8s. On my '81 CJ-5 I tried an in tank pump; this was one of the biggest mistakes that I have ever made (pulling the fuel filled tank, by hand on the side of the interstate and then again along a trail convinced me - BAD IDEA).

Enjoy!

[jeepskate]

There's a whole forum dedicated to the 4.0 swap over at www.cjoffroad.com
Tub swap is covered here and every other major Jeep forum as well and there should be a thread in the sticky for that as well.

We're always glad to clear up any confusion that may arise as you digest that info, but those are the places to start with your research...tons of info there.