Blew my motor on my 87 xj 4.0 need ideas on hat motor i can upgrade to
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Junior Member
Joined: Mar 2010
Posts: 69
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From: redwood city/ modesto
Model: Cherokee
Engine: 4.0
i have a 87 xj 4door its a 4.0 6 inline it has a 5 inch lift and its on 33's. i just blew my motor like last week. i want to upgrade to a high output motor but is it just drop the motor in and plug and play with my old harness or wat?? and also what year jeep would be the best one to get?? the one with the most power?? thanks
Member
Joined: Dec 2010
Posts: 224
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From: South Georgia
Year: 1998
Model: Cherokee
Engine: 4.0
i have a 87 xj 4door its a 4.0 6 inline it has a 5 inch lift and its on 33's. i just blew my motor like last week. i want to upgrade to a high output motor but is it just drop the motor in and plug and play with my old harness or wat?? and also what year jeep would be the best one to get?? the one with the most power?? thanks
Thread Starter
Junior Member
Joined: Mar 2010
Posts: 69
Likes: 0
From: redwood city/ modesto
Model: Cherokee
Engine: 4.0
my friend told me to get a 96-98 motor with the intake manifold and that will be pretty much the best stock setup for it for right now. any input is welcome thanks
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CF Veteran
Joined: Nov 2008
Posts: 7,874
Likes: 100
From: Northern Ontario, Canada
Year: 1990, 1999, 2000
Model: Cherokee
Engine: 4.0
you can't just throw in an H.O, it won't work.
you can use the block, but need to use your head, intake and exhaust manifolds, so you won't have the added horse power the H.O has.
you need to use your renix stuff.
mine is a 90 renix with a 95 block. no added H.O horsepower here.
the previous owner did mine and it was a pita, there is a lot of small differences to be dealt with.
just get a good renix motor and be done with it.
you can do a v8, but i don't think you're ready for that headache of a job either.
you can use the block, but need to use your head, intake and exhaust manifolds, so you won't have the added horse power the H.O has.
you need to use your renix stuff.
mine is a 90 renix with a 95 block. no added H.O horsepower here.
the previous owner did mine and it was a pita, there is a lot of small differences to be dealt with.
just get a good renix motor and be done with it.
you can do a v8, but i don't think you're ready for that headache of a job either.
Member
Joined: Jun 2011
Posts: 242
Likes: 1
From: Portersville, Pennsylvania
Year: 1997 & 1998
Model: Cherokee
Engine: 4.0
To go from 1987 to, say, 1996, it's anything but a plug & play setup. You're talking going from a pre OBD anything to an OBD II vehicle. Even with a pre 1996 OBD I setup, it's still a major undertaking. This means the electronics are totally different from soup to nuts. There are sensors, a computer, wiring, fuses, relays that your XJ never had. All have to be present for the latter day engine to work. Basically, you'd have to completely rewire your XJ to that of a '96 or whatever year you decided to go with. That doesn't even cover the emissions stuff.
You'd be a lot better off to use an era specific engine from the late '80s to 1990 or so before OBD I went into effect and do performance upgrades to it.
You'd be a lot better off to use an era specific engine from the late '80s to 1990 or so before OBD I went into effect and do performance upgrades to it.
Last edited by wjnfirearms; Jul 14, 2011 at 08:19 AM.
CF Veteran
Joined: Jun 2011
Posts: 2,858
Likes: 1
From: Nor-Cal
Year: 1990
Model: Cherokee
Engine: The venerable 4.0
Originally Posted by wjnfirearms
To go from 1987 to, say, 1996, it's anything but a plug & play setup. You're talking going from a pre OBD anything to an OBD II vehicle. Even with a pre 1996 OBD I setup, it's still a major undertaking. This means the electronics are totally different from soup to nuts. There are sensors, a computer, wiring, fuses, relays that your XJ never had. All have to be present for the latter day engine to work. Basically, you'd have to completely rewire your XJ to that of a '96 or whatever year you decided to go with. That doesn't even cover the emissions stuff.
You'd be a lot better off to use an era specific engine from the late '80s to 1990 or so before OBD I went into effect and do performance upgrades to it.
You'd be a lot better off to use an era specific engine from the late '80s to 1990 or so before OBD I went into effect and do performance upgrades to it.
CF Veteran
Joined: Jun 2011
Posts: 2,858
Likes: 1
From: Nor-Cal
Year: 1990
Model: Cherokee
Engine: The venerable 4.0
Originally Posted by Gee oh Dee
Pretty sure its pre OBD. Not OBD I.
Last edited by Slick761; Jul 14, 2011 at 09:31 AM.


