4.0 conversion in CJ7

[allabs5150]

1050893

Can anyone tell me how diffecult it would be to exchange a 4.2 with a later model 4.0 in a 79 cj 7 can i uce my factory T-18 transmission will the engine mounts, transfer case drive shafts and rears all mate with the 4.0 .......

ANy help would be graetly appriciated think I may have spun a bearing in the 4.2...................#$@$%$^&% HERE WE GO AGAIN

OH ya could I also run a carb on th 4.0 set up...or how much trouble would it be to go with the fuel injection



Thanks[addsig]

 

[flyboy]

1050903

I'm not sure if the transmission will line up. But from experiance it is a bit of a pain to switch to fuel injection you'll need the entire wire harness and computer. Better hope you are really good at troubleshooting problems. [addsig]

 

[sloop]

1050936

Yes, the motor mounts are the same and the bellhousing patterns are the same.



I am in the middle of a 4.0 conversion to replace the 258 in my '82 Wagoneer right now. There is a LOT of info out there but there are still quite a few snags and obstacles along the way. I can't tell you everything you need to know but here are a few of the issues-



4.0L HO. The '91-'95 engines are high output and have a simpler computer system than the '96 and up from what I've read. My engine is from a '93 Wrangler



fuel pump - you'll need an electric fuel pump, either an in-tank which you can get from certain year 4cyl wranglers OR an inline pump mounted near the tank like I am using. Mine cost $85 from hesco. It puts out something like 80psi I think. You'll also need a regular fuel filter after it, and a lowrestriction filter before it. all of the rubber hoses must be rated for FI



CPS- the 4.0L's have a crank position sensor on the top of the transmission bellhousing. You can either get your bellhousing drilled to fit it.. I have an auto transmission and am using Hesco's CPS relocator kit that moves it to the harmonic balancer and has a new harmonic balancer. it is $285.



Wiring/Computer- you'll need ALL of the wiring for the engine and of course the computer and you'll have to figure out how to splice in with your wiring



Water pump. I've READ that the cherokee 4.0L's all use electric fans but the wranglers have regular clutch driven fans. I think radiator hoses might be different on the cherokees too.



on the Grand Cherokees, some of the computers had a theft deterrant system that you will not let the engine run for more than a second or so



There ya go. Go to pirate4x4.com and jeepsunlimited.com and search on their forums.



[addsig]

 

[allabs5150]

1050937

Thanks Sloop........and welcome aboard, there are alotta good folks here with great jeep knowledge, and you joining us just made it better[addsig]