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-   -   YJ 2.5 engine compatibility between years (http://www.wranglerforum.com/f218/yj-2-5-engine-compatibility-between-years-239722.html)

JKU SRQ 05-02-2013 11:00 AM

YJ 2.5 engine compatibility between years
 
Working on a 1989 YJ with blown 2.5, big hole in the block. Looking at another 2.5 out of a 1993. I understand that the injection is different (TBI vs MPI), but wondering if I can install the long-block '93 engine, swapping the intake & components, or are there other major differences between them that I'm unaware of?

StanF 05-03-2013 06:44 AM

Since no one answered, I'll give you an idea. Just call an engine shop (or look online) and see what range of years they list for the 2.5L. I imagine the short blocks had a wide range of years. The long block probably not so much, but maybe.

I'm curious in the answers you get, as I might need a new engine at some point. Please post back what you find.

Hockeygeek21 05-03-2013 07:17 AM

I have a 94 and I think my block is an older on because the valve cover is different than my other 94. Both fuel injected. I don't think the blocks are any different between years

JKU SRQ 05-03-2013 07:27 AM

I used to sell parts at a salvage yard and still have contacts in the business that I've asked. Hollander is a program showing interchangable models & years. In this case, a direct swap is 1986-1990 Comanche, Wagoneer & Cherokee, 1989 Eagle Premier and 1989-1990 Wrangler. Usually it shows compatible models with minor modifications, but in this case it shows nothing else.

On the flip side, Hollander shows that the engine block and head are direct swaps from 1987 to 1995 for a Wrangler, up to 1996 on some other models (Dakota?).

I'm hoping that I can use the 1993 engine as a long block and swap the intake & fuel system from the blown 1989.

Surely someone here has gone to a different year 2.5 on their YJ... are there other fitment issues that prevent it from working? Maybe different crankshaft or something? Would really be bummed having my buddy buy an engine that we can't make fit in his rig.

JKU SRQ 05-04-2013 01:26 PM

Bought the engine... gonna do some clean up on it, change oil pan & vc gaskets, then start swapping parts over... will post progress.

JKU SRQ 05-16-2013 12:36 AM

Pulled the old engine on Saturday, swapped most parts on Sunday, and tonight the replacement engine is in... have a few things to finish up before we try to start it. Overall, it has not been terrible, but basically I approached it as installing a long block as it's definitely not a direct swap.

Don't quote me on this, but here's what I've come up with as changes to the 2.5 in the YJ's:
1987-1990 have TBI (throttle-body injection), 1991+ have MPI (multi-port), therefore fuel pump pressure is different.
1987-1989 have V-Belts, 1990 (?) and up have a single serpentine belt so everything belt-driven is different.
1987-1989 have PCV (positive crankcase ventilation) where as 1990 on up have CCV (neutral crankcase ventilation) with different valve cover fittings.


Here's some of the things that needed to be swapped over for this 1993 Wrangler 2.5 4-cylinder engine to work in my buddy's 1989 2.5 4-cylinder Wrangler:
• harmonic balancer/crank pulley, replace front seal while you're at it (early models have v-belts, later have serpentine... you'll need a 3-point puller to get it off)
• alternator & power steering pump (v-belt vs serpentine, also the alternator has different wiring connectors)
• distributor (newer one has wires for pickup coil, early does not) be sure to use a long flat screwdriver to align oil pump drive before installing or it will not fully seat, nor will your oil pump work!
• valve cover (due to PCV or CCV)
• all vac lines & injection setup
• intake & exhaust manifolds, however the gasket is the same on both
• water pump (older v-belt fan pulley rubs on newer pump)
• oil pressure sender (different wiring connector) in block near oil filter... remove sender at elbow first, then remove elbow... re-install elbow then sender
• coolant temp sender (different connector) in top of head near rear of valve cover on driver's side
• motor mounts & brackets (different mounting brackets for alt. & p.s. pump)

The MAT (manifold air temp sensor) was the only thing we removed before pulling the engine as it did not have a connector, however the wires were spliced with crimp connectors so that may have been modified previously... otherwise we did not have to cut any wires at all.

I swapped over his existing flywheel, but we installed a new clutch kit with slave cylinder since we had the engine out.

I'll likely be finishing everything up tomorrow... Buying a new water pump, and have a replacement starter to pick up (current one has a stripped stud). I'll try to post anything else that seems to come up.

AllMudd 05-16-2013 08:20 AM

Quote:

Originally Posted by JKU SRQ (Post 3714055)

Surely someone here has gone to a different year 2.5 on their YJ... are there other fitment issues that prevent it from working? Maybe different crankshaft or something? Would really be bummed having my buddy buy an engine that we can't make fit in his rig.

From what I keep reading and what I would do if my engine blew. Most just spend the money on a V8 swap. IMO you spending money that can be used to purchase a donor vehicle to accomplish the V8 swap.

JKU SRQ 05-18-2013 10:27 PM

Just for starters, doing a V8 swap would mean replacing the axles and transmission, fabricating new motor mounting points, rewiring, and many other unplanned tasks, let alone more time consuming making it all work. That would have been much more costly than the $250 used engine, new clutch kit, and new water pump plus a little time swapping parts from the blown motor.

Back on topic, it's up and running. Turned the key, cranked a little until the fuel was primed, then started right up, just like the original engine did. Aside from burping the cooling system, there was no adjusting or tweaking necessary.

Pretty sure I listed most or all of the components that need to be swapped. Had a few minor snags that weren't described well in the repair manual, but it doesn't sound like many are interested in doing an engine change to another 4-cyl so I'll spare the time typing it here. I found the compatability info I was looking... yes, it can be done, just had to do it myself to figure it out.

2xs 05-18-2013 11:34 PM

My 1990 TBI has V-belts AND an actual PCV valve...
Perhaps the switch to Serp and PCV changes was a mid year deal, Mine is also Federal emissions, if that matters.

Jrgarcia715 05-19-2013 12:38 AM

Quote:

Originally Posted by JKU SRQ (Post 3769951)
Just for starters, doing a V8 swap would mean replacing the axles and transmission, fabricating new motor mounting points, rewiring, and many other unplanned tasks, let alone more time consuming making it all work. That would have been much more costly than the $250 used engine, new clutch kit, and new water pump plus a little time swapping parts from the blown motor.

Back on topic, it's up and running. Turned the key, cranked a little until the fuel was primed, then started right up, just like the original engine did. Aside from burping the cooling system, there was no adjusting or tweaking necessary.

Pretty sure I listed most or all of the components that need to be swapped. Had a few minor snags that weren't described well in the repair manual, but it doesn't sound like many are interested in doing an engine change to another 4-cyl so I'll spare the time typing it here. I found the compatability info I was looking... yes, it can be done, just had to do it myself to figure it out.

Where did you find an 2.5l for 250?

JKU SRQ 05-19-2013 12:53 AM

It's my buddy's 89 YJ... I helped with the swap. He found it on Tampa craigslist out of a 93 with a blown tranny... guy is converting his to a complete Dodge 3/4 ton 360 Magnum drivetrain. Since I was doing a lot of the work, it was much easier (and cheaper for him) to stick with another 2.5 4 banger.

A couple months ago we found a 2.5 out of a 95 nearby for $200 but couldn't get there soon enough to pick it up, sold too quick. Wait and you'll see a good deal now and then.

JKU SRQ 05-19-2013 10:06 AM

Having worked selling parts at a salvage yard, there are usually reasons for them asking higher prices... durability, interference engines with broken timing belts, or availability. They list 2 or 3 model years as being "compatable" so that makes the availability limited. The block and head are completely identical on 87-95 models, so if you find a deal on any model year engine in that timeframe it's maybe an hour or so of swapping parts to make it a direct fit. Hope this helps someone else.


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