chance to upgrade from Renix 2.5 to 01 Dakota 2.5 questions

[81Chero]

Good evening,

Since buying a 88 pioneer for my son with the 2.5/4spd/3.31, I've been looking into getting another motor and or trans just to re-build and wait for the renix one do die..

 

Well they seem to be scarce near me and was out at a yard to look for a cluster to swap out, and I come across a hideously painted o1 Dakota with the 4cyl..

Not much if anything has been removed and thought if I can get out early one morning, I could pull the whole engine and harness for what it would cost for a long-block core +shipping to me.

I've read some of the swap to 4.0's and really don't want that for my son anyway.
Is the swap to the Chrysler MPI worth it if it's all there?  

Would I have to pull the dash harness as well for splicing? or is everything needed right in the engine compartment? (ecu and such)

I didn't read anything in the DIY section about it.

Also, wanted to know if it could be done in about a week or so? (I'm pretty decent with tools and machinery) That means running..

If its' like a month or two just to figure out the wiring, well then I'll just pull the motor and swap the short blocks out.

 

Links with pics would help out lots..

Thought I should post this instead of PM'ing folks might be better since I'm new here.

 

Thank you.

Errol

 

 

[gogmorgo]

Swapping to OBD2 is a pretty big chore. Obviously none of the engine controls will be the same, so you'll have to completely swap all the electronics in the engine. Your dash with analogue gauges will also not be compatible with the OBD2 digitals, so you'll need a new gauge set as well.

 

It's not uncommon for newer 4.0 blocks to get swapped into an older system, just changing over what needs changing, and staying with mostly Renix controls. It's much less work to do it that way than to completely change the harnesses for only a small performance gain. As the 4.0 and 2.5 share quite a few components, I don't see why you couldn't do something similar. That said, what's the point of getting a newer motor if you're just going to pull it apart and rebuild it, using none of the new control system?

[Jeep Driver]

The 2.5 block and head from '84 to '02 are all the same with 2 exceptions-

 

The older blocks have a mechanical fuel pump mount while the later blocks have it blocked off, the mount is still in the casting but solid, the later's coil is mounted there rather than just a block-off plate.

 

This is a bigger issue-

The front stub of the crank shaft is longer on the pre-'97 engines. You can use the older dampener and accessories with a '97+ shaft but you CANNOT use a '96- shaft with '97+ accessories.

[dasbulliwagen]

Pull the long block at the yard with intake and all you can get, rebuild it then swap it in your MJ with the renix when needed. In order to do an OBD swap as bolt in, you'll need a like vehicle. Keep the renix or wait for a 91 or newer MJ or XJ to get all needed parts from.

[Jeep Driver]

Pull the long block at the yard with intake and all you can get, rebuild it then swap it in your MJ with the renix when needed. In order to do an OBD swap as bolt in, you'll need a like vehicle. Keep the renix or wait for a 91 or newer MJ or XJ to get all needed parts from.

The '01 intake will not allow him to use any of the '88 accessories. He'll need  one off a '92 with a matching PS pump bracket.

[dasbulliwagen]

Yeah I forgot about that. Though I have been wondering myself about converting an mpi manifold to renix. The flow characteristics should be better than the renix manifold and it probably wouldn't take much to adapt the TBI.

[81Chero]

Thank you for all the good advise. 

This is for my son and although I have a 4.0 short block built up already, i don't need him to be getting tickets or acting stupid. The 4-cyl will suffice for now.

 

Does anyone know if the air conditioning compressor is the same between the two?

 

Another thing, Does it have 15mm bolts all over it? (I don't understand who came out with THAT SIZE??. They should be taken out in a field and beat..) Off to Harbor freight..

 

E

[gogmorgo]

What's wrong with 15mm? 15mm is a nice size. While you're at HF, pick yourself up a full metric set, and also some torx bits. There are torx bolts everywhere.

 

The 4.0 is definitely enough to get someone in trouble... but then again, so is the 85hp 1.7L in my Lada. It's more a matter of how you drive. If anything, the lack of power in the Lada makes me a more dangerous driver because I get impatient, and really pissed off at people who cut me off, or who stop in merge lanes. 

[Jeep Driver]

Yeah I forgot about that. Though I have been wondering myself about converting an mpi manifold to renix. The flow characteristics should be better than the renix manifold and it probably wouldn't take much to adapt the TBI.

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[Jeep Driver]

Thank you for all the good advise. 

This is for my son and although I have a 4.0 short block built up already, i don't need him to be getting tickets or acting stupid. The 4-cyl will suffice for now.

 

Does anyone know if the air conditioning compressor is the same between the two?

 

Another thing, Does it have 15mm bolts all over it? (I don't understand who came out with THAT SIZE??. They should be taken out in a field and beat..) Off to Harbor freight..

 

E

 

 

 

You'll have to compare the two. Two styles of compressors, different mounts, AC mount is also 1/2 of the Alt mount. Mount and compressor reflects belt alignment, just because a '97+ mount and compressor will bolt up does not mean you can use it with '88 accessories.....besides, hoses are different IIRC.

 

 

You can swap the backs of the compressors to get the hoses to match...but again......the belt alignment may be off......you'll have to compare.