Jeep LS swap for the LJ

UNSTUCK

But stuck more often.
RockChucker, I'm pretty sure you're right about them being Camaro manifolds. I got them for the Sunbeam and couldn't make them fit as they dumped too far back. They are nice though and they have the two bolt flange which is much easier to work with.

DaveB, the blockhugger center dumps have been my go-to on every LS swap I've done. It's always tight, but I've never not been able to make them work, linked or leafs. I always rout the driver side exhaust between the oil pan and flywheel housing and Y into the passenger side along the passenger side frame. Was temped once to get two passenger sides and flip it for the driver side and then route it in front of the engine. That just creates a bigger mess though with behind the axle steering.
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
I have these manifolds I'd sale for $200. You could try them out to see if they fit, first. They are brand new, but were test fit....


Also, those parts I was telling you about are for the early TJ's, like 97-02ish. I don't think they will work with your computer.

Let me think about the long arm option, but I'll likely message you about these in a week or two.
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
Another option, that I don't know the viability of, would be to consider going to a longer upper arm that sits further back on the frame? Might be enough room to make the Vette manifolds work? It looks to me like you have the LCG enduro kit from tera? long lowers and short uppers?

I am running Sanderson center dump block huggers. They work well, but changing the starter isn't ideal. I did build my exhaust in multiple pieces with v band clamps so I can easily access the starter if needed.
Yep running the Tera lcg. I'll have to look at adding the long uppers.
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
Yep my York had a shattered rod and was in pieces in the crank case. Cylinder is still good so I'm sourcing/pricing a rod if someone knows where to get one. I paid $20 for the York so I'm not too bummed, I half expected it not to work.
Spent the rest of yesterday cleaning frame rust, spraying it with rust reformer and mounting the throttle pedal.
The pedal took a while. There is a small hump in the firewall at the top right corner of the pedal. Some hammer time and nipping the corner made it fit pretty well. Think I should run it like this ?
20200211_152225.jpg
Just kidding I trimmed the bracket and pedal. I'll cut the Jeep pedal and attach it to keep the stock look and feel.
20200211_181200.jpg
Started integrating the harnesses. This seems pretty daunting but I'm actually really happy to be doing instead of scouring through diagrams.
20200211_175114.jpg
 

RockChucker

Well-Known Member
Location
Highland
Coolant temp will be 98 camaro 3 wire unit sending to the GM PCM and the Jeep dash.

I'm intrigued by this. I think I also want to do this when I put my new motor in. Is your plan to run a resistor inline on the 3rd signal wire to map it correctly to the Jeep gauge? Or are you just going to hook it up and see what happens? It would be nice to know what the Jeep signal voltages were to better know if a resistor is needed.

Camaro Sensor Specs:
GM Sensor Specs.jpg
GM Sensor Pinout.jpg

TJ Sensor Specs:
TJ Sensor Specs.jpgTJ Sensor Specs.jpg
TJ Sensor Pinout.jpg

Seems like it should be very doable though.
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
I'm intrigued by this. I think I also want to do this when I put my new motor in. Is your plan to run a resistor inline on the 3rd signal wire to map it correctly to the Jeep gauge? Or are you just going to hook it up and see what happens? It would be nice to know what the Jeep signal voltages were to better know if a resistor is needed.

Camaro Sensor Specs:
View attachment 125074
View attachment 125073

TJ Sensor Specs:
View attachment 125076View attachment 125076
View attachment 125075

Seems like it should be very doable though.
You've engineered it way farther down the path than I have. I read somewhere there was a sensor with 3 wires (2 signal) that worked, I bought it and was going to try it. Thanks for the pin outs and resistances, where by chance did you get them? I looked for about 5 minutes and then got distracted by something else.
I'm going to dive into wiring this weekend so I might be far enough into it to let you know. I'll definitely keep you posted. Better yet, you should try is and let me know what you find :D
 

RockChucker

Well-Known Member
Location
Highland
You've engineered it way farther down the path than I have. I read somewhere there was a sensor with 3 wires (2 signal) that worked, I bought it and was going to try it. Thanks for the pin outs and resistances, where by chance did you get them? I looked for about 5 minutes and then got distracted by something else.
I'm going to dive into wiring this weekend so I might be far enough into it to let you know. I'll definitely keep you posted. Better yet, you should try is and let me know what you find :D
I have access to diagrams, pinouts, troubleshooting guides and general factory service manual stuff. It makes things nice rather than spend 3 hours googling....I can find this information very quickly :cool:
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
Yesterday I got 40% of the wiring done. This is definitely the hardest part, not because it's difficult but I have to keep focused on one problem and resolve it while there are 10 other problems an inch away.

I didn't do my due diligence when pulling this motor down. I should have taken more pictures of how the GM harness laid out on the engine. I've torn down a few engines and the manufacturers don't usually put identical plugs next to each other so the harnesses usually only fit one way. When you pull a bunch of the plugs out of a harness, it's get more complicated. So word to the wise, lots of pictures are helpful. It doesn't help that I am doing some things differently the GM did and tucking wires out of the wire more.

Moving on. I have the GM harness laid out on the motor and mostly running where I want it so I put the body back on to test some ECM locations and check wire routing.
20200216_113603.jpg
Looking pretty good. I also test fit my radiator and it looks like I could probably run the mechanical fan. I will likely try the spal unit first.
I decided to mount the tach module under the brake master and the ECM will go on the back side of the driver's side inner fender. I'll route the main harness trunk under the brake not over it like in the picture.

You can see the tac module here, I've also ran all the ignition and battery power from the GM ECM over to the passenger side where they will tie into the underhood fuse box. You can also see some of the wires that will go through the firewall via the grommet at the top right between the brake and the Jeep harness.
20200216_195149.jpg

Passenger side shot. You might notice I have tucked the injector harness under the intake to clean things up a bit.
20200216_195155.jpg

I think I'm going to mount the fuse box in the factory location, or as close as I can with the high lines fenders. I had planned on mounting it over the battery covering the connectors on the Jeep PCM but not sure it will fit well there.

Need to finish up the last dozen or so connections and I can start looming.
I am going to order a tach emulator, T case shifter and transmission shift linkage from Novak this week.
 
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RockChucker

Well-Known Member
Location
Highland
If you can, I'd recommend mounting your tach emulator inside the cab, or in a place that doesn't get heat soaked. I have found that mine starts to send a screwy signal when it gets warm (aided by really warm summer days too). My tach will bounce all over the place like it's on crack. I'm planning on moving mine inside the cab when I put my new motor in (also because I need to get the tach signal out of it for my 6L90 controller and want to mount that in the cab as well).
 

DaveB

Long Jeep Fan
Location
Holladay, Utah
I have the mechanical fan on my CJ and have around 2 inches of clearance to the radiator. I'm in the process of making an air shroud by shrinking a Yukon shroud. Looks good so far.
 
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glockman

I hate Jeep trucks
Location
Pleasant Grove
If you can, I'd recommend mounting your tach emulator inside the cab, or in a place that doesn't get heat soaked. I have found that mine starts to send a screwy signal when it gets warm (aided by really warm summer days too). My tach will bounce all over the place like it's on crack. I'm planning on moving mine inside the cab when I put my new motor in (also because I need to get the tach signal out of it for my 6L90 controller and want to mount that in the cab as well).
Good info. Thanks for the heads up. I ordered the tech emulator, transfer case shifter and transmission linkage from Novak yesterday.
I am blown away at how fast you are moving along with this.
I have to daily drive a crew cab long bed, race season is in progress and it needs to be done and tested prior to jeep safari. Lots of motivation ?
I have the mechanical fan on my CJ and have around 2 inches of clearance to the radiator. I'm in the process of making and air shroud by shrinking a Yukon shroud. Looks good so far.
The shroud is one reason I'm going to try the electric fan first. It's got one built in so that saves me a step.
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
After messing around with connections for a couple days, I've decided to use a blue sea auxiliary fuse box instead of tie everything into the Jeep box.
There are only two empty blade fuse slots in the Jeep box, the rest are jcase. In case anyone wonders metrapck 150 terminals fit mini bus fuses but I can't locate any new jcase fuse terminals so I'd have to go grab some from a junkyard fuse box. That is more ghetto than a nice auxiliary fuse box in my opinion. Plus I have some lights and several other accessories that will be better off tied into the aux fuse box.

Most of the wiring is ran just need to tie things into power and ground and secure all the wiring in the trans tunnel and around the oil pan.
 
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glockman

I hate Jeep trucks
Location
Pleasant Grove
Got power steering connected. My reservior has the extra port for hydro boost. It's the upper port.
20200218_131526.jpg
Since I'm not using hydro boost, it needed to be plugged. I tapped it with an M8 tap and stuck a bolt in with some rtv.
20200218_132025.jpg
20200218_132336.jpg
The return line sticks out too far and contacts the steering shaft and the frame.
20200218_132738.jpg
After looking at my options I decided to cut it down and bend the remaining tube.
20200218_133144.jpg
The Jeep high pressure hose threaded into the pump but was way too long and had funky bends in the hard line. The newer tj's have a different steering box so hose and rubber couldn't flar a new hose. They ended up cutting the box side hard line and putting a compression fitting on it to a new rubber line with the correct hard line bends at the pump end. It fits pretty nicely but it was $$.
20200218_134435.jpg
20200218_134354.jpg
One more item off the list.
Also drilled and tapped the oil cooler block off plate with a 1/8 npt to mount the Jeep oil pressure sending unit.
20200218_144104.jpg
It's tucks nicely out of the way with enough clearance to still unplug it.
20200218_144805.jpg

I also go the starter and fuel pump relays wired. It's getting closer.
 

DaveB

Long Jeep Fan
Location
Holladay, Utah
I had the same issue with my power steering return line. I broke out the oxy acetylene torch heated it up and carefully bent it so it would clear the steering shaft.
 
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