'97 Swap Question

[Rymanrph]

I found a '97 XJ 4.0 2wd auto that I thought about buying for a parts vehicle (front clip, doors, interior, motor, etc.). Currently I have a '90 4wd with a '95 transmission and transfer case. Can I mate the 5 speed to the newer motor without any problems? I didn't know if I'd run into any problems with the ecu and wiring harness. I wouldn't mind having an auto, but its only 2wd, so I'd rather just save the money and keep my 5spd.

[Rymanrph]

Anybody? If I have to swap the computer or wiring harness, would it just have to be from a 5 spd XJ (2wd or 4wd) or would it need to be specifically from a 5spd 4wd truck? I kinda need to know so I can move forward with this specific XJ or keep looking. This running example is $1300 and all the other ones I can find are $3k and up. I haven't been able to find a wrecked one that wasn't a front end collision.

[shark]

if your mj is a 4.0 the new 4.0 should bolt in with no problems. reuse all your current sensors. you might also need to relocate some of those sensors.

[Rymanrph]

I'm swapping everything (engine, dash, wiring, etc.). The only thing I want to keep is my current transmission (5spd 4wd) because the one in the XJ is a 2wd automatic.

[HOrnbrod]

In that case if you keep the 5-spd you'll have to find an manual tranny OBDII PCM for it. Pretty sure you can't use the wrong PCM on an OBDII. OBDI 95 and below yes, but not OBDII.

[kastein]

In that case if you keep the 5-spd you'll have to find an manual tranny OBDII PCM for it. Pretty sure you can't use the wrong PCM on an OBDII. OBDI 95 and below yes, but not OBDII.

Yep.

 

Well really it depends on how picky you are about the CEL coming on... if you don't like it you will have to use an MT ECU for it instead of the AT one. You'll also need to do a little wire splicing for the clutch safety switch and reverse light switch on the trans instead of the NSS on the slushbox. It will run and drive fine with the CEL on from either a disconnected transmission (but the TCU present) or both the trans and TCU disconnected, but may fail your inspection and you won't know when the ECU actually has something to complain about.

[Rymanrph]

So if I get a manual ECU and do the wiring splicing will I get any CELs? Correct me if I'm wrong, but you're saying I would splice the wiring for the neutral safety switch on the auto harness to the clutch safety switch on my current setup? If that's all there is to it, then it would be a lot easier than having to buy a whole new harness. A new ECU should be $100-$200 and easily found, but I think the harness might be more $ and a lot harder to find.

[kastein]

Correct. Basically you just wire the clutch safety switch up to the terminals that are connected in P/N on an NSS, and the reverse light switch up to the terminals that are connected together in R on an NSS. Done!

 

Finding a manual ECU for a 97 might be difficult, might not be.

[Rymanrph]

Correct. Basically you just wire the clutch safety switch up to the terminals that are connected in P/N on an NSS, and the reverse light switch up to the terminals that are connected together in R on an NSS. Done!

 

Finding a manual ECU for a 97 might be difficult, might not be.

 

Well, that doesn't sound too bad. I'm really excited about this. My biggest concern is the whole fuel tank/sender/pump issue and the fact that I won't be able to drive it for months on end. I just got done with my current interior upgrade, rust repair and 4wd swap.

 

There are a couple companies on ebay that will program and send you one as long as you have a VIN to give them. Otherwise www.car-part.com for a junkyard search.

[JeepcoMJ]

Just put 98 5 zpeed parts into 98 auto, required complete swap to 98 wiring harness. The wiring for the engine bay and the air bag systems plus the engine/trans wiring are NOT compatible.

 

You will need a complete 5 speed harness to do the swap. Steering column is optional but a good idea. ECU are different, and flywheel will need to be for the year of engine operating system you are using.

[Rymanrph]

Just put 98 5 zpeed parts into 98 auto, required complete swap to 98 wiring harness. The wiring for the engine bay and the air bag systems plus the engine/trans wiring are NOT compatible.

 

You will need a complete 5 speed harness to do the swap. Steering column is optional but a good idea. ECU are different, and flywheel will need to be for the year of engine operating system you are using.

 

Ouch. Sounds like I'd be better off finding a 4wd auto trans. Is the wiring harness different for 4wd vs. 2wd?

[kastein]

Just put 98 5 zpeed parts into 98 auto, required complete swap to 98 wiring harness. The wiring for the engine bay and the air bag systems plus the engine/trans wiring are NOT compatible.

 

You will need a complete 5 speed harness to do the swap. Steering column is optional but a good idea. ECU are different, and flywheel will need to be for the year of engine operating system you are using.

Wait, the AIR BAG system is different depending on what transmission is installed? That confuses me a bit. What's different about the steering column / wiring?

 

Definite good point on the flywheel, I had forgotten that part.

[JeepcoMJ]

Just put 98 5 zpeed parts into 98 auto, required complete swap to 98 wiring harness. The wiring for the engine bay and the air bag systems plus the engine/trans wiring are NOT compatible.

 

You will need a complete 5 speed harness to do the swap. Steering column is optional but a good idea. ECU are different, and flywheel will need to be for the year of engine operating system you are using.

Wait, the AIR BAG system is different depending on what transmission is installed? That confuses me a bit. What's different about the steering column / wiring?

 

Definite good point on the flywheel, I had forgotten that part.

 

Steering column has the key safety built in on a 5 speed, on an auto it runs a cable to the shifter on the floor. The dash wiring is the same, but from the firewall forward is different. The engine bay harness has 2 extra connectors in the auto for the trans control and . Also, the TCM wiring is part of the engine bay harness. The air bag wiring is different, and the BCM seems to be located under the seat on 5 speeds, and under the center console. That could b a difference between 97 and 98 though...

 

But basically, you can halfass the wiring to work...or do it right. Either way will function, but one is a PITA to make work.

[kastein]

Ahhhh that makes sense. Never knew about the steering column difference.

 

The BCM doesn't exist on XJs, you're probably talking about the ACM (airbag control module) which was initially under the driver's seat but was moved to under the console for corrosion reasons in a TSB/recall.

 

The extra wiring for the TCU and stuff can just be ignored when going from auto to manual - going the other way, I fully agree it'd be a half @$$ job. The extra connectors under the hood likewise, except you'd take the old cable from the NSS and chop it up, then splice in some wires for the clutch safety switch and reverse switch. That only counts as a quarter @$$ job in my book :rotf:

 

I agree that to do a full OEM lookalike install on a 5speed swap you'd have to pull all sorts of stuff up and swap it.

[JeepcoMJ]

The nss will have to be wired to itself, and reverse lights to ur 95 wiring.

 

The 97+ 5 speed nss is actually part of the master cylinder.

 

I still think it's halfass. I don't like splicing factory stuff...somehow there's always issues later on, no matter how well it's done

 

Side note, the ACM was located under the console in the 97, under driver's seat in the 98.

[kastein]

Yeah, I don't like splicing factory wiring but only under certain circumstances. Whenever I do, instead of chopping up the actual body/engine harness, I go to the junkyard and get the harness that normally plugs into whatever I'm connecting to, and basically build a custom cable that plugs in just like an OEM one would. I have serious wiring OCD...

 

Interesting that the clutch safety switch is built into the master cylinder - assuming it's the clutch master, not the brake master?

[JeepcoMJ]

Yup, clutch master

[Rymanrph]

Well from what everyone has said, it sounds like if I move forward (with this specific truck) the easiest option would be to find a 4wd AW4. If I ever decide to swap, then I can just hang on to my current parts and look for a 5 speed harness, computer and flywheel.

[JeepcoMJ]

Yup