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'89 4.0 is it fuel injected?

cheepin

NAXJA Forum User
Location
Parachute CO.
I was just given an '89 2 door 2wd XJ.I haven't seen it up close for while.Thinking if it had fuel injection would it be easily swapped onto a 80 CJ 258?
 
Damn. I'd take the rest off of you if you were closer...

All 4.0's are port fuel injected. If you swap the cylinder head over as well, you'll get a slight boost in compression and a better breathing cylinder head. The head should bolt right up, and you can use the 258 head gasket, I think. If you Google around a bit, you'll find some writeups with more detail than I can give you (I haven't done my own yet - I don't have a 258 lying about to check on, and I don't have a 258 head and a 242 head where I can do a side-by-side on them...)

5-90
 
XgeekstarX said:
Whats your problem?Just asked a simple question.I haven't got to look at it up close yet or even got it yet.I am getting it from a coworker.He used to drive it to work.
I have been doing some research on injecting my CJ.I have found other years but nothing on the '89.
 
There is also at least one add-on FI kit for the 258 out there that doesn't require you to swap your head - I know MOPAR put one out, and Howell might have as well. They are, I believe, TBI kits - meaning a central fuel injector, rather than "port" injectors for each cylinder. Therefore, some carburettor issues still apply.

I think you'd be better off transplanting the system and cylinder head, if you don't mind doing the work. You'll have to bring the ECU over, most of the engine bay wiring, and the head and top end along for the ride, but it may be worth it.

Alternatively, if this isn't your DD and you don't mind doing some more work, you could pull the 242 block out of the XJ, have it cleaned up and +.030/+.060 (whichever - probably .030, since it would give you room for later) and put the 258 crank and connecting rods in with the 242 pistons, giving you a stroker and more displacement than either engine. This would also work out to be more low-end torque, which is what you'd want anyhow.

Granted, that's only really an option if you have something else to drive while you're working on the CJ, but it's something to think about. You'd still have to move the control systems over...

I with someone would give ME an XJ - or better, an MJ! I need a pickup truck, I'm just suffering from a lack of readies...

5-90
 
From the articles I've read, swapping on the 4.0 head on the 258 nets 40hp. I think they use the '92 HO head. There was a special part number for this. I think Hesco might still market such a swap. The power is about the same as a 4.0L though.
Tom
 
4.0 L Cylinder Head Conversion on 258
4.2L Head Conversion
Two articles on the head swap.

I do think 5-90 said it the best, this is what i would do, extending off of the above articles.
5-90 said:
I think you'd be better off transplanting the system and cylinder head, if you don't mind doing the work. You'll have to bring the ECU over, most of the engine bay wiring, and the head and top end along for the ride, but it may be worth it.

Not knowing enough on my end about the mechanics (bolt patterns, clearances) of the CJ and it electronics I can only assume you would have to get the head in there and then fit it for exhaust, and the flex plate plus the distributor for the timing for the RENIX control, and I probably have missed a bunch of other things. Timing the engine might be the hardest part of the swap depending on the way things bolt.
IMO swapping electronics is not hard, did that on a Toyota truck, went from a carbed 20(R think that's right) to a 92 ingected 22(R? been a bit the years have slipped might be wrong on them), was a pain (the dash was the worst not the engine) but it can be done. I'm thinking if you have both vehicals it would be easier, I did in the above switch made it nice to walk over and get the senosr/switch whatever I forgot to pull out with the wiring harness.
I have been thinking about doing this but haven't sat down and scrubbed the books to find a plan yet, I would really be interested in seeing the results if you take on the task. Heck if I was closer I'd be helpping if I could.
 
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Thanks,I should be getting it this weekend.I will look it over.I guess it runs and drives but the front end has the wobble going on.I may just fix the front and drive it for work.My Cj-7 is not my DD.But I might wait until this winter to tear into doing the fuel injection.It runs and wheels really good right now.I will think about the stroker.Maybe find another 258 to use for parts.Keep the jeep running until ready to swap.I just don't want to have my rig down just when wheeling season is just starting!!I did this before and ended up missing out all summer!!!!!
 
If you're going to do a stroker, you'll need the 4.0 setup (obviously!) and the crankshaft and connecting rods from a 258.

The 4.0 pistons can be reused, or you can bore the 4.0 block out to accept larger slugs - and use those. You'll still want the 258 crankshaft (3.895" stroke, vice 3.44") and the connecting rods (I believe they're 5.875" long, vice 6.125" for the 242. I'd have to check on that...) but using the shorter 258 rods will neatly accommodate the longer 258 stroke.

Your head is casting #2686, and the one referenced (OBD-I) is casting #7120. However, if you get a #7120 head, you'll also want the manifolds that go with it at least - in 1991, the 242 head was revised for better airflow, and one of the changes was raising the intake ports. The RENIX manifold (what you've got) won't work without some field modification, but I believe the fuel rail from RENIX might bolt onto the manifold for the #7120 head. Can anyone confirm? Also, the throttle bodies are different - you'll need either an adapter (the RENIX has a 3-bolt mounting, the HO a 4-bolt) or you'll need to adapt the TPS somehow - I haven't looked into that yet.

Still, the #2686 head is a significant improvement over the #2685 (which should be what's on the 258 - it was the last 258 head design, for the "wide deck" engines, I believe they're called. The later ones have a common mounting pattern with the 242.)

You might also want to search for Dr. Dyno's site - he's got some promising stroker patterns - and trawl around on the strokers egroup (groups.yahoo.com/group/strokers) - which is dedicated to improving AMC I6 performance. I've got a book on the subject as well, but it's more general improvements than stroker-specific. It may make a handy reference for you - I wrote it with the AMC I6 in mind.

5-90
 
Found this link on a 4.2 to 4.0 swap today, will post below in case the site ever goes away. Just some extra info to keep on mind.

4.2L to 4.0L Engine Swap

When doing any kind of engine swap, the best course of action is to buy
everything you might need at the same time. It's both easier and cheaper
than making a return trip. Tip: the '91 and newer 4.0L motors have less
plumbing and use the superior Mopar EFI system.

In this case, you'll need the:
- motor and all its accessories (any Jeep 4.0L should do
- auto or manual tranny makes no difference)
- Crank Position Sensor (CPS) - get a CPS that matches the
transmission to which you will be bolting the 4.0L,
either automatic or manual.
- flywheel or flex plate
- computer (type will depend on your transmission)
- exhaust manifold and O2 sensor
- charcoal cannister
- maybe the catalytic converter, depending on your local
motor vehicle regulations
- fuel tank & pump

Fuel injection systems utilize high pressures so make sure you use fuel
lines and clamps rated for foel injection use. The fuel rail input is
at the rear, near the firewall. The return is at the front.

The 4.2L motor mounts will work fine with the 4.0L although the 4.0L
block's rear motor mount hole on the driver's side is metric (it's
best to take all the motor mount bits when you buy the motor).

The expensive add-on you'll need for this swap is related to the
Crank Position Sensor (CPS). It is mounted on top of the bellhousing.
You have three options:


1. Do It Yourself Cut a hole in your bellhousing so that you can bolt in the CPS. This is the cheapest way to do it and the possibility of screwing up the job is very high.
2. Buy an Advance Adapters Bellhousing It will have the CPS hole built-in to it and can bolt up to the transmission of your choice, although some of these adapters do not support the CPS. For these, AA suggests choice 3. Note: the 4.2L bellhousing (YJ or CJ) will bolt up to the 4.0L.
3. Buy a Hesco or Mopar CPS Their sensor mounts to the harmonic damper at the front of the engine. You must specify auto or manual tranny.



Speaking of sensors, you will also need a vehicle speed sensor (VSS).
This attaches to the speedometer output on your transfer case. Both Hesco
and Mopar can supply this.

Note: this information has been collected through various sources. None
of it is guaranteed. It is simply presented to give you a good idea of
what would be required to do a 4.0L swap in a 4.2L-equipped Jeep. As with
any swap, unexpected problems will crop-up.

...lars
 
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