98 Engine in 92 XJ advice.

I need some clarification on what exactly to do to get this jeep to run I've been searching and found a lot of good info. As far as I can tell the previous owner had NO clue on what he was doing. I want to run this off the obd1 computer.

Current messed up setup

1992 XJ
1998 ZJ engine/head
He tried to rewrire the 98 dizzy to work
Cut the fuel injector harness and clamped on 98 connectors
Used 98 injectors
used 98 sensors1
luckily used 92 Flexplate

I've located a stock 93 XJ at a junkyard locally and it is complete and I was wanting to confirm the parts I will need.

Dizzy
stock wire harness (other one has been slightly hacked)
all stock sensors
injectors/rail
Do I use the obd1 throttle body?

If you are wondering why I picked this mess up I can tell you for $150.00 You'd do the same :rof: And quick intro as this is my first post. I've owned a 1997 XJ before and loved it, had it for 5 years sold it and have wanted one back. My wife drives an 05 Grand and I have a 1985 CJ8. Currently unemployed by the government shutdown...normally a UH60 crewchief.

Aaron

Does anyone have any advice? I just want to make sure I purchase the correct parts at the salvage yard. Thanks again!

Aaron

The only difference between the two engines is the head casting I believe. You want to reuse all of the 92 sensors and injectors and harness and just swap the motor itself.

Might have need to add a coolant temp sensor in the head but I can't remember which years have two sensors.

It sounds like you may have gotten a bad deal if you bought it that way. Swapping a motor is not all that complicated. I have a 92 in my 97. Swapped right in. Reused all the 97 electronics and swapped the throttle body from the 97 onto the 92 motor.

http://www.naxja.org/forum/showthread.php?t=1015349

Some reading while you wait for someone that knows the answer.

Thanks for the information guys! I'm not to worried about a bad deal...spending $150 on a complete Cherokee does not worry me to bad.

westvirginia24976 said:

http://www.naxja.org/forum/showthread.php?t=1015349

Some reading while you wait for someone that knows the answer.

Click to expand...

That link has nothing to do with the OPs question.

I would grab the complete engine harness and injectors and sensors and throttle body fuel rail. Grab all of the stuff you listed. There should be no splicing to make the dizzy work. The cap rotor should be the same as well as the sensor for the camshaft position sensor that is located under the rotor. All of the sensors need to be for the Vehicle that the motor is swapping into ie the 92.

It sounds like the po was hacking some stuff together. I would start from scratch.

Thanks for the reply Gordo! I was thinking the same thing I just wanted to be sure before I spent the money on everything. And yes the PO really had no clue on what he was doing...

I want that truck thats across the road!

Nice spot!! That's my neighbors J10. Rebuilt engine/drivetrain the only thing left is the actually body to make it perfect. He has daily drove it for the last 5 years I have lived here.

GordoSmasho said:

The only difference between the two engines is the head casting I believe. You want to reuse all of the 92 sensors and injectors and harness and just swap the motor itself.

Might have need to add a coolant temp sensor in the head but I can't remember which years have two sensors.

It sounds like you may have gotten a bad deal if you bought it that way. Swapping a motor is not all that complicated. I have a 92 in my 97. Swapped right in. Reused all the 97 electronics and swapped the throttle body from the 97 onto the 92 motor.

Click to expand...

The 98' block is stiffer (more ribs), the 98' piston skirts are made of graphite and the pistons are lighter aluminum pistons. The cam is also different. It is a dual ratio cam that favors exhaust, unlike the 91-95 single pattern cam and is advanced one more degree. The valve springs on the 98' are lighter rate valve springs. Overall, the 98' engine has a larger/broader torque curve compare to the 92'. The 98' engine makes peak torque at 3000 rpms instead of 3950 rpms. Also, the 0630 and 7120 are identical. The only difference is that the 7120 has the rear coolant port. Good luck!

Agreed that the internals are a bit different but the physical aspects and connections are the same except for the coolant port on the back. Your going to have do a bit of research on that part.

streetxj - Did all the changes you touched on happen in 96 or 98. I have two 97s and I was wondering if that was the difference between the two that i feel. One has a bit more pep down lower in the power band. One has the stock motor with a 94 head on it. The other has a stock complete 92 motor.

Simplest solution to your problem is to replace the hacked loom and wrong year parts with the correct year. Simple.

Should only take a few hours to a day to swap it all over depending on how 'clean' you want it to look.

GordoSmasho said:

That link has nothing to do with the OPs question.

Click to expand...

I beg to differ, perhaps not answering all his questions, but some relevant information for sure. He is dealing with two different Jeeps from different years and I believe some of the information would help him to understand what he needed especially if the links to other similar threads are followed.

If you say so.

GordoSmasho said:

Agreed that the internals are a bit different but the physical aspects and connections are the same except for the coolant port on the back. Your going to have do a bit of research on that part.

streetxj - Did all the changes you touched on happen in 96 or 98. I have two 97s and I was wondering if that was the difference between the two that i feel. One has a bit more pep down lower in the power band. One has the stock motor with a 94 head on it. The other has a stock complete 92 motor.

Click to expand...

The revised engine was first used in the 96' models.