MPI/Engine swap (wish me luck!)

Tore apart my jeep yesterday, got the front end basically stripped down to the engine and wiring harness.

Now I get to isolate/cut/solder every single TBI wire into my new MPI harness (woo, fun!). I know I'm a bit insane for doing it, but I love the challenge!

Hopefully tonight I'll pull the engine, order the clutch kit, water pump, t-stat, and um... air filter? I'll get some pictures and a nice list of how much this beast cost...

Anyways, wish me luck on a successful swap!

good luck, and don't forget the pics

four_shot said:

good luck, and don't forget the pics

Click to expand...

Haha, thanks... Taking a break for lunch, just rode to wal mart for some rotella t, heat shrink, soldering wire, and some food!

ENGINE!

New Harness

New intake, alternator, power steering pump, and their mounts.

More pics in a bit

I apologize for the cell phone pics, but they did turn out better than I expected...


Fenders that aint goin' back on

trash that is sitting on the trash

Cracked manifold

Best friend

New sensors, t-stat housing, coil,, and a little bit of the power steering bracket on top of the new gasket set

DESTRUCTION

would it not have been easier to swap in a new harness, or is this the easy way.

I plan on taking my 4cy to MPI, but I was gonna do it with as much as a complete transfer as possible.

^^^^

X2, I was gonna mention something similar

I swapped a complete 4.0 in place of my TBI 2.5 on my 87 MJ....all I did was replace the 2.5 underhood harness and ECU with a 4.0 harness and 'puter, and it fired right up.

Props to ya, though......either way you do it, you'll definately see a performance improvement :cheers:

Jeff

edit: here's my thread on my 4.0 swap so you can see what I mean about the harness. If I can offer any other info you might need, lemme know. I did ALOT of research before I started turning wrenches on mine.....

http://www.naxja.org/forum/showthread.php?t=969906

I wish I had a 2.5 to play with. All I have is this stroker (which actually isn't running right now).

Just kidding and good luck with the swap. subscribed.

Jeff in VA said:

^^^^

X2, I was gonna mention something similar

I swapped a complete 4.0 in place of my TBI 2.5 on my 87 MJ....all I did was replace the 2.5 underhood harness and ECU with a 4.0 harness and 'puter, and it fired right up.

Props to ya, though......either way you do it, you'll definately see a performance improvement :cheers:

Jeff

edit: here's my thread on my 4.0 swap so you can see what I mean about the harness. If I can offer any other info you might need, lemme know. I did ALOT of research before I started turning wrenches on mine.....

http://www.naxja.org/forum/showthread.php?t=969906

Click to expand...

Yeah, see you did a renix-renix swap... I'm doing renix-HO swap (persay, the 2.5 wasn't HO of course, but it's an identical system).

And yeah, if you can, get both the interior and exterior harnesses from an XJ if you are gonna do this. Post 91 2.5 XJ's are IMPOSSIBLE to find for me, so I had to get a YJ engine/body harness from someone parting it out online. The YJ body wiring is... to say the least inadequate for the XJ, so no dice there.

I think I could pull the Body harness from a Junkyard XJ, but then I get to go into rewiring the dash and guages... Maybe in the future, but for now I'll stick to only touching the engine bay.

I'm hitting the FSM's right now for some good wiring harness sorting! yay!

Also, the new engine isn't anything too special. I bought it to rebuild it (duh), but found out it was only 50,000 miles old, was bored .030 over, and has a weird offset on the crankshaft bearings. Who ever rebuilt before me was dumb, it looked like they put synthetic in it and called it a life... never changed the oil. Oh yeah, and they ran straight water for coolant... ugh people are so dumb.

Anyways, cleared the sludge, most of the rust, and most of the coating left by the synthetic. 3 angle valve job, new cam and lifters, planed head/block, then rebuilt it. We went to a guy out here that builds uber-hi-po engines, he gave us the best price out of every shop in town. My dad paid for most of the engine work, while I actually helped the guy at the shop to clean everything and reassemble. GREAT learning experience, and got a discount for me being a nice apprentice, haha.

Doing this swap myself. Going from a carbed 2.5 in my 85 wagoneer to an MPI 2.5, aw4 tranny, and a 231. Lots to do!!

85xjwoody said:

Doing this swap myself. Going from a carbed 2.5 in my 85 wagoneer to an MPI 2.5, aw4 tranny, and a 231. Lots to do!!

Click to expand...

wow, the aw4 just makes things harder! Haha, did you get the interior harness too?

I have been putting off my wire problems because I'm super tired from work and just want to pound on things, ie the vibration dampener and all the engine accessory brackets. The engine is coming together so pretty that it's amazing... Everything is either black or aluminum, so it has some nice contrast... and fits together with the rest of what I want with the jeep; black, a little silver/chrome, and tan.

I have the complete donor vehicle for the wiring. Still have lots to do to get the aw4 to work properly.

Back from the dead for a little help!

Almost all wired up, everything mechanical is together, distributor is indexed properly (I hope). My problem, for now, is that the engine isn't cranking and the fuel pump relay seems to be clicking.

I'm willing to bet the battery is just too drained for the starter to crank, I tried to hotwire it, but... yeah... the negative battery post ended up blowing molten lead in my face... I'm kinda used to it because of all the soldering I've done, but it wasn't the intended action for sure! Any input?

Also, if the relay is clicking, what does it mean? I don't have any fuel in the tank, but it's just odd...

Everything is pretty confusing, and I'll try to work it out, but for now I'll get some updated pictures for you guys. This time higher quality!

Low voltage can make the relays click.

winterbeater said:

Low voltage can make the relays click.

Click to expand...

That sounds like a good answer... I'm gonna get the cooling system back together, run the vac lines, and put some gas in the tank, that should be the last steps to get'r running. THEN I'll get a good battery in there to try it again.

Gonna get lunch, then I'll upload some pics.

Woo, got it running! Badly though... Idle starts off high and just keeps going up, so I just end up shutting it off before I can listen for any weird sounds or anything. I'm suspecting the IAC is seized, as it and the TPS are the only small electrical/sensor parts I haven't replaced, but I'll run some tests before I start throwing parts at it.

For now; pictures!
Custom cable-to-electronic speed sensor and unfinished associated wiring



Driver-side view, and a small glimpse of unfinished wiring


Front view




Passenger side, bypassed the heater core for now... A/C will come soon.


EGR tube block-off plate.


It's been a long road for sure, I can't wait to actually drive the thing again, but as usual there are millions of little things to clean up/upgrade before I get anywhere near done... As done as a jeep ever gets of course.

A quick list of specs;
88 XJ TBI engine bored .030, full valve job and new cam/timing set ($$$)
94 YJ Engine harness/ECU
2001(2?)~ intake manifold, fuel rail, and 24lb injectors
Pre-97 4.0TB
97+ fuel tank/pump
98 TJ accessory brackets/P/S pump and Reservior
New water pump
New T-stat housing
New coil, and All sensors except TPS and IAC motor
94~ distributor/cap (guy said it had less than a couple hundred on it)
New 90amp alternator
Newish cheapo energizer battery (replaced right before the tear-down)
Newish cheapo radiator (plans to upgrade to 87+ 4.0 radiator support/radiator with one or two electric fans)
New 94 flywheel
Rebuilt ax-5 transmission w/severe gear full synth amsoil ($$$$)

I'm sure I've missed some things, but I got all the important stuff. Talk about basardization though! I know it's weird for me to be running the newer returnless fuel system with the older controls, but I couldn't find anything else at all for sale, and at the time of purchase I didn't have a proper job. If it doesn't work out right I'll first switch to 5.0 19lb injectors, then go backwards with everything else if that runs to rich or anything.

There are little things like reverse lights, wipers, blower motor, and eventually A/C wiring (already have compressor, just need drier/accumulator and to figure out wiring) that still need to be soldered in.

That's all for now, help me out if you can guys!

Maybe I should ask for this to be move to modified tech? It's mostly OEM parts being swapped for OEM parts, so I thought this would be the more appropriate forum, but I'm trying to get some response to questions of an experimental nature... This was a huge undertaking, especially for an eighteen-year-old... I just need some advice/feedback and I'll be happy.

If a mod or any authority says I can I'll start a thread in modified tech, if not I'll try to find a more helpful forum altogether... thanks to those who have at least tried to help/discuss this with me!

wow, the 2.5 is TBI??? didn't know that

Slip Kid said:

wow, the 2.5 is TBI??? didn't know that

Click to expand...

86-90 only, 91-93 are MPI, 94-95 SMPFI, all with return-style fuel systems and a vaccuum controlled FPR. 96 is kinda a hodgepodge, but that's only for the XJ, because the Wrangler didn't have a 96 year at all. 97 is a fuel-bypass FPR/single-line fuel system, as well as some added safety controls and an extra 02 sensor in 98~, then two more in '00 I think... No 2.5 in 01 XJ's, but was used until ~02 in TJ's.

Drove it under its' own power today! Everything is only half hooked up, no evap system, no CCV, no blower motor, no heater, no washers, no fuel gauge, no vac disco, no vaccuum canister, and a whole bunch of things need to be secured properly...

Definitely more power, better throttle response, etc. but I need to tie everything up and weld some holes in the exhaust past the muffler. There is some kind of rattle near the starter, it's either the down pipe rattling against the oil pan, or the tranny cover isn't secured properly.

Oh and as for the high idle, It was just a leak at the intake manifold gasket, I mostly torqued it down correctly but still have some work ahead to ensure no more vac leaks. Hoping to bring it to peak efficiency in the process!

The starter problem was a bum ground on the starter relay itself, just jumpered it for now to start it up with the key alone.