mndiesel Posted April 8, 2014 Share Posted April 8, 2014 So I've had my 1986 Comanche XLS Long bed 4 speed with blown 2.5L engine for almost 1 year. Originally my plan was to swap in a diesel engine, life got in the way and my comanche is still sitting in the garage. Today I came across this craigslist ad: http://rmn.craigslist.org/pts/4400603875.html $800 for a 2.5L engine with AX5 transmission out of a TJ. Is this the same engine from my Comanche? If so, I am now thinking maybe I should just pick this up and get my Comanche working quickly. My original plans for a diesel can wait I'd much rather have a working truck. I'm in MN and love FT 4wd. If I get this 2.5L with AX5 to put in would you guys go for an NP242 21 spline or NP228? Thanks for any advice! Link to comment Share on other sites More sharing options...
dasbulliwagen Posted April 8, 2014 Share Posted April 8, 2014 Yes the 2.5 is the same block and trans. The TJ has a different injection system than your MJ though. You could swap all the original stuff over from your old one though (intake, exhaust, sensors, acessories) and it will all be good. Stay away from the NP228. It is a nightmare of vacuum lines and not very strong. Someone else should chime in about the 242. Good luck! Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted April 8, 2014 Share Posted April 8, 2014 Yes, it will work but as stated, the TJ one is MPFI. Swap the intake and accessories and you'll be good to go. As for transfercase, 242 all day over the 228. Link to comment Share on other sites More sharing options...
Comanchemodder Posted April 8, 2014 Share Posted April 8, 2014 You will need to choose if you retain the RENIX system or the TJ system. Differences: 1) ECU. If the engine comes with the full harness, this is do-able. 2) Distributor 3) Flywheel 4) accessory pullies my be offset slightly different (oil slinger?) 5) The Alternator. The TJ has an externally regulated. Your 86 has internal. 6) Fuel pump. The TJ requires the higher pressure. There may be some others. Basically you need to decide if you retain your RENIX or not. If yes, its a no brainer easy. I managed to do it, and if I can, anyone on this board can. If you want the MPI, there a couple of more things to take care of. Link to comment Share on other sites More sharing options...
mndiesel Posted April 8, 2014 Author Share Posted April 8, 2014 Wow, this is fantastic information thanks guys! Thank you for the great info. I am very glad I asked because I would have guessed it was simple drop in place and that's not the case. I am thinking I should look for a rebuild 2.5 that will be simple drop in place for my MJ. Comanchemodder - how do you like driving your 87 with a 2.5? I realize mine is 4x4, I'm not afraid of slow cars though, I have an 83 300TD wagon that puts around. Link to comment Share on other sites More sharing options...
Comanchemodder Posted April 8, 2014 Share Posted April 8, 2014 I am thinking I should look for a rebuild 2.5 that will be simple drop in place for my MJ. But the TJ is 2.5L is drop in. You just need to unbolt some stuff to get it as a long block form. If you want to keep your existing ECU and RENIX injector system, its an easy swap. If you want to use the TJ system, there are a few more things (my list). Link to comment Share on other sites More sharing options...
mndiesel Posted April 9, 2014 Author Share Posted April 9, 2014 I never thought I was going to go this route so I had not checked out rebuilt 2.5L engines, but I've spent the past hour looking online and they seem pretty reasonable. For a few hundred dollars more than the used one I found I could get a rebuilt one like here: http://www.rebuiltenginestore.com/engine/87/1986_jeep_comanche_engine_2.5liter.html Has anyone bought a rebuilt 2.5L? If so, anything to look out for or anyone have a recommended place? there are several places with prices from 1,100-2,000ish Link to comment Share on other sites More sharing options...
benjy_26 Posted April 10, 2014 Share Posted April 10, 2014 That's WAY too much to pay for a rebuilt engine. If you do the grunt work yourself and ask aroung your area for reasonably priced machine shops (and score a few deals on parts), a sub 1K rebuild is entirely do-able. Heck, I spent around that to get a 4.0 overbored, valve job'd, AND scored a hi-po cam. Link to comment Share on other sites More sharing options...
benjy_26 Posted April 10, 2014 Share Posted April 10, 2014 BTW, HOW blown is your 2.5? Can you see into the block without unbolting anything? ;) Link to comment Share on other sites More sharing options...
mndiesel Posted April 10, 2014 Author Share Posted April 10, 2014 Wow, sub $1,000 is very cheap. Here's the thing is I bought the truck with a blown engine and it taken apart. The previous owner was chasing a pheasant and over revved the engine, the rod went right through the top of the piston! He started the tear down so you can see the top of the piston but that's where he left off... My original plan was to swap a diesel in. I just don't have the free time I used to, so I thought putting the original engine back in is a better plan (with potential swap to AX5 for that 5th gear). Link to comment Share on other sites More sharing options...
benjy_26 Posted April 10, 2014 Share Posted April 10, 2014 In your situation, I'd just get a JY engine that's in decent condition for a couple Benjamins. Link to comment Share on other sites More sharing options...
mndiesel Posted April 10, 2014 Author Share Posted April 10, 2014 In your situation, I'd just get a JY engine that's in decent condition for a couple Benjamins. Thanks for the advice, I think that's a good plan. I will start watching craigslist closely... Link to comment Share on other sites More sharing options...
dasbulliwagen Posted April 10, 2014 Share Posted April 10, 2014 I bought a complete running used 2.5 from someone doing a v8 swap for $100.00 Keep an eye on the classifieds here and in other Jeep sites and one should pop up pretty quickly. If you have ay local 4x4 websites you could look there too. I'm not sure where you are, but I know the local one to me is www.nc4x4.com, of in the Great lakes region there is www.greatlakes4x4.com A search for a site in your local area should turn something up. Good luck. Link to comment Share on other sites More sharing options...
mndiesel Posted April 11, 2014 Author Share Posted April 11, 2014 Wow, $100 that is a deal! Thanks for the tips, I am in Minneapolis, MN and will be watching that great lakes forum. Link to comment Share on other sites More sharing options...
neohic Posted April 11, 2014 Share Posted April 11, 2014 Have a look around MN-Jeep.com also. :thumbsup: Link to comment Share on other sites More sharing options...
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