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motor swap...99 GC to 90 Cherokee 4.0L

willy rich

NAXJA Forum User
Location
warren, michigan
Well...tried the search feature and didnt get what i was looking for or just dont know how to use it properly :doh:
anyways....the motor in my 90 Cherokee is done...i have the oppurtunity to purchase the motor out of a 99 Grand Cherokee...for 100 buxs...its has like 40k miles on it...the GC is wrecked and id b the one doin the pulling of the motor....a few things ive noticed on some sites and advice from others is to grab everything ie: the computer...the wire harness..and the exhaust manifold....
i do plan on converting the 90 to a open type cooling system..i just need a lil more info the swap and more direction on whats gonna be involed in it so im asking you guys for some help ( who better else then XJ owners :helpme: )so any info you guys could give me would be greatly appreciated tips...advice...what to grab off GC and what not too....THNXS..Willy
 
I am doing the same thing except mine is from a 99 XJ, here is what you will need:-
96 and up gas tank with fuel pump and wiring
93? and up Gaugle cluster since its electronic
96 XJ dash wiring harness
since you are getting the GC one, the aleternator might me mounted in a different location, trsy to get as much as yu can from it.

ravi
 
so everything u said should be from a xj???...i know i can get it all fromt the GC but dont know if there the same or not....i can get the complete under hood harness and dash harness and cluster from the GC and the fuel pump and harness too....the guy said take what i need so im gonna grab everything that i can ;)
 
willy rich said:
so everything u said should be from a xj???...i know i can get it all fromt the GC but dont know if there the same or not....i can get the complete under hood harness and dash harness and cluster from the GC and the fuel pump and harness too....the guy said take what i need so im gonna grab everything that i can ;)

Just get the complete Motor and the engine wiring harness, cause they are the same. Now if you want your gauges to work, you will need an electronic gauge cluster from an XJ cause that will fit in yours(93?-96), thats why i said about the cluster, and same with the dash wiring, now if you can get the GC gas tank to fit in your XJ then go for it, sorry if i confused you.

ravi
 
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Get the complete motor and accessories but don't plan on using any of the electronics from the new engine. Your ECU is the renix type and the 99 GC would be OBDII which of course are not compatible. I'm putting a motor from a 96 xj into my 89 xj and what I found would probably be the easiest way would be swap all the old accessories onto the new engine on the passenger side. Replace the intake manifold with one from a 91-95 4.0 and also the fuel rail. The reason for the manifold swap is how the power steering pump mounts. Using the 91-95 would result in the least hassle. If you have an automotic tranny you will need to adapt the tps on the throttle body to renix, but if you have a manual I believe you can simply wire in the new tps. Use the old distribute. Your exhaust manifold and downpipe will not work. I'm having a custom one bent up for mine. Swap all of your old fuel injection sensors to the new block. Use the old flexplate on the new motor. I currently am using the injectors from my 89 but I may switch over to the 96 injectors if the 89's don't work well. You will need a new throttle cable and transmission kickdown cable. Your cruise control may or may not work. That's all I can think of for now. It's not too difficult but expect to be making several trips to a junkyard for parts. I can't tell you yet if it's worth it.
 
Freshly hijacked from the graveyard...
My question ts a bit more complex, I have a '94 ZJ 4.0 HO and a '86 XJ 2.46, my problem is: if I were to move over ALL of the electronics from the ZJ into the XJ (heavy on modification), how could I work the Gauges, OBDI, etc...
using the ZJ as it is is is not an option because it was smashed hard in the rear.
Sorry for the hijack, but I posted my own question and no one responded.
 
crazyoffroader said:
Freshly hijacked from the graveyard...
My question ts a bit more complex, I have a '94 ZJ 4.0 HO and a '86 XJ 2.46, my problem is: if I were to move over ALL of the electronics from the ZJ into the XJ (heavy on modification), how could I work the Gauges, OBDI, etc...
using the ZJ as it is is is not an option because it was smashed hard in the rear.
Sorry for the hijack, but I posted my own question and no one responded.

It's not worth swapping the 4.0 into the 2.8L early xj's. A GM 3.4 is almost a direct bolt in. Here's the link bud:

http://www.off-road.com/jeep/cherokee/xjtech/engine/28-34swap.html
Enjoy. :)
Troy
 
kunaji said:
Get the complete motor and accessories but don't plan on using any of the electronics from the new engine. Your ECU is the renix type and the 99 GC would be OBDII which of course are not compatible. I'm putting a motor from a 96 xj into my 89 xj and what I found would probably be the easiest way would be swap all the old accessories onto the new engine on the passenger side. Replace the intake manifold with one from a 91-95 4.0 and also the fuel rail. The reason for the manifold swap is how the power steering pump mounts. Using the 91-95 would result in the least hassle. If you have an automotic tranny you will need to adapt the tps on the throttle body to renix, but if you have a manual I believe you can simply wire in the new tps. Use the old distribute. Your exhaust manifold and downpipe will not work. I'm having a custom one bent up for mine. Swap all of your old fuel injection sensors to the new block. Use the old flexplate on the new motor. I currently am using the injectors from my 89 but I may switch over to the 96 injectors if the 89's don't work well. You will need a new throttle cable and transmission kickdown cable. Your cruise control may or may not work. That's all I can think of for now. It's not too difficult but expect to be making several trips to a junkyard for parts. I can't tell you yet if it's worth it.

What about the engine mounts. I'm about to do this to my 89 xj with a 97 4.0l. I am going to step up to some heavy duty mounts anyways but should I order some mounts for a 97 engine or 89. And aren't the injectors larger on the 96. Why limit more fuel flow with your pre-ported set up or what ever makes a high-output ho.
 
Engine mounts are the same.

The fuel injectors on the '96 are also rated at a higher psi than the '89 injectors. I haven't driven my jeep enough since I put the new motor in to see how well the smaller injectors are working with the higher fuel pressure of the 91-95 fuel pressure regulator. I have assumed though, in the absence of more research, that the '89 injectors put out enough fuel because of the higher fuel pressure. The Renix setup was designed to work with the non-ho 4.0, but the HO should be within its ability to adapt. I am no expert on this issue though and if anyone is willing to correct me, then I'm willing to listen.
 
willy rich said:
Well...tried the search feature and didnt get what i was looking for or just dont know how to use it properly :doh:
anyways....the motor in my 90 Cherokee is done...i have the oppurtunity to purchase the motor out of a 99 Grand Cherokee...for 100 buxs...its has like 40k miles on it...the GC is wrecked and id b the one doin the pulling of the motor....a few things ive noticed on some sites and advice from others is to grab everything ie: the computer...the wire harness..and the exhaust manifold....
i do plan on converting the 90 to a open type cooling system..i just need a lil more info the swap and more direction on whats gonna be involed in it so im asking you guys for some help ( who better else then XJ owners :helpme: )so any info you guys could give me would be greatly appreciated tips...advice...what to grab off GC and what not too....THNXS..Willy

By far the easiest thing to do would be to swap in the '99 long block and use the '99 intake manifold, TB, and exhaust manifold. Use everything else from your '90 XJ including the Renix engine computer, wiring harness, sensors, fuel rail, and injectors. You'll need to adapt the Renix TPS to the '99 TB but that isn't difficult. Everything else will be more or less plugn'play. If your injectors are old, swap in a set of Ford 19lb'ers.
 
What about the gas tank that rav mentioned, I don't see why that would be necessary? And Kunaji said the exauhst manifold wouldn't work. Is this true from xj to xj motor years or just an xj to zj motor swap.
 
The gas tank can be used or not. The reason the tank would need to be swapped is in '96 the 4.0 got a fuel rail with no pressure regulator. The regulator was moved onto the fuel pump and the fuel pump won't just swap into the older tank. Either way, fuel line work will also need to be done.

The renix exhaust manifold will not work with an HO motor. Any HO exhaust manifold should work with any HO 4.0. I don't know if the manifold is the same on the zj though.

The Renix fuel rail will not work with the new intake manifold so you would also need the fuel rail from a 91-95 HO so you get the pressure regulator. Or swap the tank and use the 99 fuel rail.
 
Thanx kunaji, this site is deffinatly a keeper. I doubt there is something some one doesn't know about an xj around here.
One more thing, what if I decide to bore it and put i dunno maybey a 4.6l stroker kit in it and need an adjustable fuel pressure regulator. Do the newer models have fuel pressure regulator built in to fuel pump or bolted on outside.
 
Keep in mind the 99 ZJ 4.0 doesn't use a distributor. I'm not sure if there is just a block off plate and you'd be able to install one? Stock, it's got the coil on plugs system.. so trying to make that work with a Renix computer would be interesting.

The pressure regulator is in the tank I believe. I do know it's 46PSI for sure.
 
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