4-cylinder engines: upgrades through the years

Correct, I just decided to splice the part of the chassis harness heading to the back of the vehicle and keep everything attached further down as it was.

The truck was wrecked in the front end when I got it, so not everything lined up perfectly on the header panel I put on. The spacers will make it all tight, but you'll never notice from looking at it that it's not perfect when I'm done.

Comanche's are cool, but I'd probably just get a Toyota next time. Solid Axle Swap stuff is cake for me compared to this stuff, and some of the newer 4-cylinder toys have about 155hp vs. the 117-130 of a Comanche. Either that or chop a cherokee and turn it into a truck. That would have been easier for me too, but I guess that's how a learning curve works.
 
xj92 said:
Correct, I just decided to splice the part of the chassis harness heading to the back of the vehicle and keep everything attached further down as it was.

The truck was wrecked in the front end when I got it, so not everything lined up perfectly on the header panel I put on. The spacers will make it all tight, but you'll never notice from looking at it that it's not perfect when I'm done.

Comanche's are cool, but I'd probably just get a Toyota next time. Solid Axle Swap stuff is cake for me compared to this stuff, and some of the newer 4-cylinder toys have about 155hp vs. the 117-130 of a Comanche. Either that or chop a cherokee and turn it into a truck. That would have been easier for me too, but I guess that's how a learning curve works.

I am going to try to splice the engine harness into the dash harness in order to bypass having to get a whole body harness... not to mention my stuff is from a YJ... I've checked XJ's (4.0) of the same year, and their interior harness doesn't match up, there are two extra plugs running inside (or outside? who knows??) that the YJ doesn't have.

I'm glad you are almost done with it! I'm not a practical person, and while I can get a 2.46 short bed single cab 2000 tacoma for the price of a head/gasket rebuild, I'd rather look for a comanche for sale around here, because I love them! My dad needs either my XJ or a work truck of his own for when I move away, so we'll see what happens when it happens...

Chopping my XJ... I wouldn't mind... put a comanche or CJ tailgate on it and I'll be good! Haha... dreams... dreams...

For now, my dad and I are gonna assemble a rebuild kit around .030 over pistons and the RVOB4 cam/lifter kit, remove and dissassemble the engine, then take the block/head to mexico and have it bored/shaved and a valve/angle job done... All the in-town shops want to "inspect" the engine before deciding to do anything, there's probably an extra 200-300 in that alone... I'd rather pull it and everything myself...

Oh yeah, I blew a piston ring or two if I didn't mention it...
 
  • finish swapping the brake & clutch pedals - done
    [*]hook up the plungers to them - done

    [*]hook up the heater controls to the chassis harness
    [*]get the a/c lines hooked up and charge it
    [*]install the dash & gauge cluster
    [*]bleed the clutch & brakes
    [*]tighten up the loose re flex joints in my lca's
    [*]wire the high speed on the electric fan
    [*]replace the bench seat with the 2-dr xj buckets & console I got
    [*]put some spacers in and tighten down the header panel
  • front bumper -done

My taurus fan isn't kicking on, and I've narrowed it down to the temp switch. I think it's because of the mounting and the fact that it's dry because of trapped air as somebody mentioned to me quite a while ago. Where are some other good mounting places? I previously had it off the thermostat housing. How about inline in one of the radiator hoses or heater hoses?
 
xj92 said:
My taurus fan isn't kicking on, and I've narrowed it down to the temp switch. I think it's because of the mounting and the fact that it's dry because of trapped air as somebody mentioned to me quite a while ago. Where are some other good mounting places? I previously had it off the thermostat housing. How about inline in one of the radiator hoses or heater hoses?

Well how hard have you tried to burp the system? What part of the t-stat housing is it running off? There's a nice little spot on the front of mine that would be PERFECT for drilling and threading...

But yeah, I'm sure the bottom radiator hose is gonna have the least amount of air pockets...
 
I stuck it in the heater hose coming off the t-stat housing yesterday but the e-fan still isn't kicking on when it should so I'll have to see if the actual switch is OK or what is going on next time I get a chance to work on it. I'd really love to just wire it into the stock temp switch, but I need to study the function of both switches and how they work to see if that's feasible or not. I've driven the truck around short distances and it's definitely quicker than before. The ported head, conical air filter, newer intake manifold, & MPI should all have contributed.
 
xj92 said:
I stuck it in the heater hose coming off the t-stat housing yesterday but the e-fan still isn't kicking on when it should so I'll have to see if the actual switch is OK or what is going on next time I get a chance to work on it. I'd really love to just wire it into the stock temp switch, but I need to study the function of both switches and how they work to see if that's feasible or not. I've driven the truck around short distances and it's definitely quicker than before. The ported head, conical air filter, newer intake manifold, & MPI should all have contributed.

Do you mean switches, or thermostatic sensors? It could just be a relay on what ever controller you are using. If not, then definately try to splice into the stock sensor to see if it works.

An idea for you; get three different temperatures of water in cups, and one ohmmeter. Test the resistance across both of the sensor's pins in each cup... and you know what to do.

You also have a 4.0 throttle body, right? Consider a cowl-type snorkle or something to get fresh air into the conical filter, I've read that if kept in the engine compartment, you'll lose a good amount of torque from it.
 
isnt there a way to run the MPI part separate from the rest of the truck? I mean is it really this complex?
I have been trying to wrap my head around this topic for a few days now and I get the jist of what is going on and I am interested in doing something similar as I am not digging my carb.
This thread is smashing my hopes of an easy fuel injected conversion on the cheap.
 
grande said:
isnt there a way to run the MPI part separate from the rest of the truck? I mean is it really this complex?
I have been trying to wrap my head around this topic for a few days now and I get the jist of what is going on and I am interested in doing something similar as I am not digging my carb.
This thread is smashing my hopes of an easy fuel injected conversion on the cheap.
what do you mean, "separate?"

Yeah... it's pretty complex, but your carb system is probably worse anyways...

IF you can get ahold of a whole engine with everything attached on the cheap, then you'll save yourself a huge amount and have a newer engine...

You'll also want a matching year engine harness and body harness for simplicity. Grab a matching year gas tank/pump from any XJ and you'll be pretty set!

MY conversion is overly complex because I'm a cheap bastard and insist on doing my own wiring and such... but now I need a good engine so I'll see what happens...

To xj92: how did you deal with an XJ fuel pump in the MJ gas tank, does it fit like normal?

Edit: and grande, your jeep is still freaking awesome!
 
Thanks for the compliment.

What I meant was can we not just do a bare bones MPI...ie supply power to things that need power and forget about tying it into our existing harness aside from an ignition/run source?
 
grande said:
Thanks for the compliment.

What I meant was can we not just do a bare bones MPI...ie supply power to things that need power and forget about tying it into our existing harness aside from an ignition/run source?

Well... I'm pretty much trying that... I think the fuse panels (interior) are all the same pinout up to 96... but I have to check that...

The engine compartment side of the fuse panel (or the Bung as it's called I think) is identical across vehicles (YJ, XJ, ZJ), but there are extra wires that run through the firewall on the XJ and ZJ that you wont see on the YJ... at least in post 91 years.

I have a YJ engine harness (also have interior, but not being used), which kinda resembles my current one in that there aren't a large amount of wires running in to the cab. I'm trying to label them all so I can figure out where to splice them in to the current one...

I may have to keep the TBI ECU in order to make the interior still work, but I'll make a plan either way...
 
You can do the engine standalone, and keep the chassis harness stock. But the EFI needs the input from all the sensors to run properly, ie crank position sensor & new flywheel, cam position sensor & new distributor with that sensor, temp sensor, throttle position, mass airflow, manifold absolute pressure, etc. And you'll need the rear fuel pump setup and wiring for that. That wiring usually comes off of the chassis harness. Now that I'm almost all of the way through it, I could do it again cheaper & easier, but it's been a long nightmare to get this far and if I could rewind everything, get my time & money back, I would.

I had to get a Comanche-specific sending unit. It uses the same pump as a Cherokee, but the metal frame that holds the pump is different. I tried xj ones and they wouldn't work. I think I have 2 or 3 xj sending units & fuel pumps left over that I didn't end up using cause they wouldn't work with the mj fuel tank.
 
Last edited:
xj92 said:
You can do the engine standalone, and keep the chassis harness stock. But the EFI needs the input from all the sensors to run properly, ie crank position sensor & new flywheel, cam position sensor & new distributor with that sensor, temp sensor, throttle position, mass airflow, manifold absolute pressure, etc. And you'll need the rear fuel pump setup and wiring for that. That wiring usually comes off of the chassis harness. Now that I'm almost all of the way through it, I could do it again cheaper & easier, but it's been a long nightmare to get this far and if I could rewind everything, get my time & money back, I would.

I had to get a Comanche-specific sending unit. It uses the same pump as a Cherokee, but the metal frame that holds the pump is different. I tried xj ones and they wouldn't work. I think I have 2 or 3 xj sending units & fuel pumps left over that I didn't end up using cause they wouldn't work with the mj fuel tank.

duh, didn't think about the fact that the MJ was made until 92, so there should be some HO fuel pumps available...

where is tempe in relation to other parts of phoenix? I'll be going up to peoria within the month I hope and wouldn't mind picking up a fuel pump or any spare parts you have for a price...
 
I'm about an hour and a half north of Phoenix in Prescott Valley and would love to get rid of anything extra I have left over. Just let me know if you decide to come up this far.
 
xj92 said:
I'm about an hour and a half north of Phoenix in Prescott Valley and would love to get rid of anything extra I have left over. Just let me know if you decide to come up this far.

DANG! sorry... haha, I was probably remembering someone else' location, but I wouldn't mind going up there for some extra parts and to check out the MJ!

... I'm going up to tow a donor XJ back down, the wiring harness is burning ECU's, but the jeep is mechanically sound. It's cheap and has an RE lift, so I think It'll pay itself off...
 
I ripped out the whole interior today. Got the heater & dash back in. Then spent the rest of the day removing the brackets from the MJ bench seat and putting them on a 2-door XJ bucket seat. I only finished the driver seat so far, but it's much more comfortable than the old bench. I got a complete gray interior from the junkyard last Monday to replace the old marroon stuff. Even got carpet, headliner, etc. Now if I could just get the e-fan working. It doesn't overheat even without a fan though. I'm sure the 4.0L radiator on a 2.5 helps some. I have to clean up some minor rust on the floor before putting the carpet in though.
 
That's pretty awesome, post up pics on a separate thread once you have it done!

It looks like I may get an engine real cheap locally, redo all the seals, the oil pump, and piston rings (we can hone it here). Then do a valve job and possibly get the RV0B4 cam and lifter kit. If I can ever get the distributor and power steering pump from a guy I sent money to (hope it doesn't turn in to a scam... it looked like it shouldn't have... ah...), then I'll do the MPI conversion while the engine is out (should be easier?) also...

I'm still interested in the jeep from peoria, and need to visit my sister and all the college friends up there, so We'll see what happens when it does happen...
 
I found this on ebay, and I tought it was interesting.... a neon srt/pt cruiser turbo adapter for Jeep 4cyl engines:
http://motors.shop.ebay.com/merchant/puresand

And here's the forum talking about it. I didn't have time to read the entire thread, but I think allot of you 4 banger guys will find it interesting.
http://www.reno4x4.com/forum/showthread.php?t=5362



.


one problem, 2.4's were never used with the XJ... it would be cool to swap a turbo srt 2.4 in, but might as well do something more substantial...
 
Didn't the TJ use the same 4cyl found in our XJs?
Yes, until 03 or 04... can't remember specifically... at that point the AMC 2.5 (actually 2.46, but semantics!) was replaced with the ChryCo 2.4L, which shares it's internals with the 2.0T and 2.2 in the Pt Cruiser (at least I'm pretty sure those sizes are correct).

As you should know, the XJ never made it past 2001... except for in china where it lasted until 2006... at that point it had either a turbodiesel or a 2.46 mitsubishi motor (I'm pretty sure)... I remember reading somewhere that chrysler was sharing motors with mitsu, the "world" engine or something, but I don't think the 2.46 and the 2.4 were the same...

It definately is a viable swap for someone with a pre 87 XJ, because it should slip right in unlike most other Engines, but the price is way up there. Considering you'll be pulling a darned new engine from a TJ, buying an adapter plate for the manifolds, then buying the manifolds and control system and... well everything else (kinda like our MPI swaps!).

It would be easier to just buy a 2.0T from a PT Cruiser or what ever the neon srt4 has and swapping it in... but that will be hard because you'll have to adapt a transverse engine and it's motor mounts to fit in the RWD cherokee... plus it'll cost...

AH... obviously I've thought about some of these things...
 
Back
Top