• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

'88 to '98 Swap

J

jkh533

NAXJA Forum User
Location
Kansas
I didn't even know where to start searching so I will just come out and ask.
My son has an '88 XJ that has a good motor and lift but a lot of small issues. We have found a '98 with a bad motor but seems to be in real good shape. I am wondering if his 4.0 will bolt up under the fuel injection system on the '98 along with his lift kit?
No more than I know about XJ's I would think everything would but wanted to make sure.
Thanks in advance for any help.
 
Well after posting this I thought why not google lift kits and I saw where that will not be an issue.
Looking on another site I saw where the injection system, as I knew, was different along with the head and intake. Can anyone confirm this or can the newer injection bolt up to the older intake?
 
All suspension parts are the same in all xj's but motor im not to sure it might be the same for the mounts :dunno:
but here is some random motor info i found on some forum
4.0L I6 "Power Tech" - 177 hp @ 4750 rpm, 220 ft lb @ 4000 rpm - used 87-90
4.0L I6 MPI "Power Tech HO" (High Output) - 190 hp @ 4750 rpm, 220 ft lb @ 4,000 rpm - used in 91-95 and updated in 96-01 to 225 ft lb torque @ 3000 rpm (00-01 models use a distributorless ignition system)
 
It will work.

You will have slightly less HP, but everything should work, just use all of the electronics, manifolds, flywheel/flexplate, brackets, etc., from the 98.
 
joe_peters said:
It will work.

You will have slightly less HP, but everything should work, just use all of the electronics, manifolds, flywheel/flexplate, brackets, etc., from the 98.
Click to expand...
arnt the exhaust ports in a diff location on the rnix then the 98? same with intake ports?
 
joe_peters said:
It will work.

You will have slightly less HP, but everything should work, just use all of the electronics, manifolds, flywheel/flexplate, brackets, etc., from the 98.
Click to expand...

You say manifolds, you mean intake and exhaust? No big deal to swap of coarse just clarifying.

Thanks for all the responses, my son kinda got turned of with all the little things and I think we can get him interested in taking it wheeling again if this happens :greensmok
 
Yeah, essentially you are just going to use the long block from the 88.
 
i would honestly sugest trying to find a ho motor in your local classifieds, also are you sure its the motor thats bad
 
If its a manual transmission you'll have issues with the pilot bearing. I have a 95 HO engine in a 87 and I had to buy a special pilot bushing from Advanced Adapters because the crank is different as is the hole diameter for the transmission input shaft. If you have an auto, or at least if the 98 is auto, then the flex plate should fit fine.
 
Alex E said:
If its a manual transmission you'll have issues with the pilot bearing. I have a 95 HO engine in a 87 and I had to buy a special pilot bushing from Advanced Adapters because the crank is different as is the hole diameter for the transmission input shaft. If you have an auto, or at least if the 98 is auto, then the flex plate should fit fine.
Click to expand...

Both Autos

i would honestly sugest trying to find a ho motor in your local classifieds, also are you sure its the motor thats bad
Click to expand...

I appreciate the response but he is getting ready for college so we just want to get the thing running now then maybe later we can rebuild the HO. I am not sure the motor is bad but the body and interior is much better than what he has so even if we need to do some injection system work it may be worth it?
 
I have a 96 block in my 88 with no problems, just switch out the engine block and keep your heads and all the electronics and you will have a pretty simple swap.
 
Okay now for a tranny question.
I have searched and found that one difference between the 88 and 98 trannies are 2 speed sensors opposed to 1. Question is, can I swap out bell housings and run the 88 tranny with the 98 bell housing and speed sensor? Main reason for this is, one we know the 88 has a good tranny, two it will be easier to do during the motor swap and three the 98 has fluid coming out of the coollant lines that look like old motor oil instead of tranny fluid!
Thanks for all the above responses, I try to search the best I can but man there is so much junk to sift through!
 
Well i discovered the difference in spline count and difference in the number of pins on the plug in. The spline count is no big deal because we have the old t-case. But i think the speed sensor may be different? Any input on if I can make this work with I got?
 
cant you just switch out the sensors? Mayby you can remove the sensor and put the other one back in it's place, you know the same thing you would do if the sensor went bad. There has to be a procedure for that somewhere. I really don't know but it is just an idea.
 
Well thats what I was wondering?
All I know is his '88 tranny is fine and I know nothing about the old one.
 
My best guess would be that it is a direct swap esp if it is the same transmission just from different years, I dont think they changed the housings.
 
You can't use the 88 tranny with the 98 electronics. The 98 has an extra input speed sensor in the front of the tranny (it's not in the bellhousing), and the rear sensor is both a different type and number of pulses per revolution. As Joe noted, you need to keep the 98 flexplate with the 98 electronics.

My vote would be to sell the 89 and buy a known good HO engine or a quality re-manufactured engine.
 
You must log in or register to reply here.

Similar threads

L
Realistic MPG 4.0/AW4 33's with 4.56 gears
Replies
12
Views
200
Black_Black
B
H
Oil pressure sender 98 vs 99
Replies
14
Views
2K
hbar..
H
S
98 A/C resurrection
Replies
15
Views
3K
XJlimitedx99
X
L
Manual to Auto transmission swap
Replies
9
Views
207
lvcanyoneer1
L
S
98 XJ manual ignition problem
2
Replies
20
Views
4K
SurplusFan98
S
Back
Top