Another LS Swap: L92 & 6l80e into a '94 LC (4 Viewers)

[Scalpel]

TOYOTA WIRING...

This is one of those posts that probably won't make a lot of sense until you're staring at the wires. I don't have a lot of meaningful pictures here. Hopefully the instructions are enough. The EWD was very helpful here:

This link was very helpful but it wasn't perfect: Vortec Swap - Pin Out Sheets - https://forum.ih8mud.com/threads/vortec-swap-pin-out-sheets.944939/

Deviations from above link:

IH1 –
pin 22 removed (fuel pump rewired)
pin 8 no relay. 6L80e transmission wants to see 12v when brakes applied
Pin 23 removed
Pin 20 removed
Pins 5 & 6 left in place. The ‘branch’ or ‘split’ from pin 5 (yellow wire) was simply removed and the wire was spliced back together.
Pin 9 is used as a trigger wire for the relay labeled “Keyed Power.” (Coming later) This relay powers the bus bar and is hot in crank and run.
IH2-
Pin 11 removed

Any wires that ran to gray ECU plugs were depinned and removed.

IH3 disappears completely

Coil wires were depinned from plug over the driver's side fender

All EFI wires removed from fuse block over DS fender. This left me with one loose ground wire.

IH2: Pins 4-8 run to the console and will be connected to the shifter (we'll discuss that later)

IH1: Pin 3 runs to the console (will be used for reverse lights / dash indicator later)
Pin 14 goes to console (Park/Neutral safety switch) to close the circuit and send signal to starter solenoid to allow it to turn over. Power output from P/N switches directed to relay that closes when in either gear - we'll get to this in more detail later.
I had depinned 5&6 but had been reluctant to pull them from the square transfer case plug. These were removed and the empty slots in the plug filled with silicone.


This was also the time to open up the fuse/relay block over the DS wheel well and remove unnecessary wires as noted above.

 

[Scalpel]

This might not be the most logical place to include this, but I'd mentioned bus bars previously. I put them next to the battery. You can just barely see them on the right side of the pic on the right. The red wires are hot in crank & run. Black are obviously ground.

The battery box did have to be trimmed a little to accomodate the loom containing these wires:

 

[Scalpel]

After considering my options I ultimately decided to mount the GM ECM on the firewall directly behind the engine. No regrets on that decision.

 

[Scalpel]

ADDRESSING THE LS HARNESS:

This link was very helpful, but again not perfect: E38 ECM Connector Pinouts - http://lt1swap.com/E38%20ECM%20Connector%20Pinouts.htm

I depinned the relays for electric fans. Seems like there were a handful of guys that had done this swap with electric fans who struggled with overheating issues. I've never had a problem and am glad I went with a mechanical fan.

Discovered the X109 plug gets removed completely

Rather than depinning pin 59, it was used to ground a relay that gives switched power to the transmission

Leave J1 pin 57 as this is necessary for the Dakota Digital cruise control module (We'll talk more about that later)

A/C compressor trigger wire from Toyota (connected to small triangular plug on PS wheel well) was simply soldered to the LS A/C trigger wire. When we tried testing this, it wouldn't engage the clutch in the compressor. Although NOT in the EWD, there is a pressure switch in the A/C line in front of the battery. The clutch will not engage unless the system is pressurized.

Removed the heavier (10 or 12g) purple wire to the starter solenoid as the Toyota wire was used for this.

Real estate was limited in the fuse/relay block. For this reason wires were bundled as such:
1. Coil Packs
2. Injectors
3. ECM/TCM
4. O2 / MAF

I decided to put the OBD2 on a metal pillar just to the right of the driver's right lower leg. This kept it out of sight but easily accessible. You do not need to run any GMLAN wires through the BCM. Just bypass it.

Putting it all together...

 

[Scalpel]

BCM: We'll talk more about it later. We worked pretty hard at getting it to provide cruise control, tap shifting, tow/sport mode (we did get all these features functional - just not through the BCM). Ultimately it wasn't worth it or we just couldn't make it happen. We did use the BCM, but only to provide regulated power for tap shifting and cruise control. Only used plugs C1 & C3 on the BCM.

C1-4 is a regulated 5v output that is later used to set up cruise control
C1-14 is for switched power in
C1-17 is a regulated 12v output that is later used for tap shifting
C1-21 is switched power in

C3-1 is ground
C3-2 is for switched power in
C3-3 is for switched power in
C3-5 is ground

All others were depinned. Only those listed are necessary.

A subtle warning to those not using a 2007 - we noticed in the GM EWD there were differences from year to year in the BCM pinouts. For reference I've attached the pinouts for C1 & C3 in the 2007:

C1

PIN #	COLOR	FUNCTION
1​	***	Not Used		Depinned
2​	PK/BK	Ignition 0 Voltage		Depinned
3​	GY	Cruise Control Switch Signal		Depinned
4​	WH	5-Volt Reference	Wired to VSS CC input after SGT-100BT	CORRECT / FINISHED
5​	L-GN	Windshield Wiper Switch High Signal		Depinned
6​	L-GN	Steering Wheel Control Switch Signal		Depinned
7​	***	Not Used		Depinned
8​	TN/BK	Low Reference		Depinned
9​	L-BU	Windshield Wiper Switch Low Signal		Depinned
10​	***	Not Used		Depinned
11​	***	Not Used		Depinned
12​	***	Not Used		Depinned
13​	***	Not Used		Depinned
14​	PK	Ignition 1 Voltage	Switched Power	CORRECT / FINISHED
15​	D-GN	Hazard Switch Left Turn Signal		Depinned
16​	TN	Hazard Switch Rigth Turn Signal		Depinned
17​	PK	12-Volt Reference	Power Source for TUTD	CORRECT / FINISHED
18​	YE	Headlamp Dimmer Switch Signal		Depinned
19​	WH	Hazard Switch Signal		Depinned
20​	PU	Tap Up/Tap Down Switch Signal		Depinned
21​	BN	Ignition 1 Voltage	Switched Power	CORRECT / FINISHED
22​	***	Not Used		Depinned
23​	L-BU	Tow/Haul Switch Signal		Depinned
24​	PK	Windshield Washer Swith Signal		Depinned
25​	YE	Headlamp Flash to Pass Signal		Depinned
26​	TN/WH	A/T Shift Lock Solenoid Supply Voltage		Depinned
27​	***	Not Used		Depinned

C3

PIN #	COLOR	FUNCTION
1​	BK/WH	Ground	Ground	CORRECT / FINISHED
2​	RD/WH	Battery Positive Voltage	Switched Power	CORRECT / FINISHED
3​	RD/WH	Battery Positive Voltage	Switched Power	CORRECT / FINISHED
4​	***	Not Used		Depinned
5​	BK/WH	Ground	Ground	CORRECT / FINISHED
6​	***	Not Used		Depinned
7​	***	Not Used		Depinned
8​	TN/BK	High Speed GMLAN Serial Data Bus +		Depinned
9​	TN	High Speed GMLAN Serial Data Bus -		Depinned
10​	D-GN	Low Speed GMLAN Serial Data		Depinned
11​	D-GN	Instrument Panel Lamps Dimmer Switch Signal		Depinned
12​	OG/WH	12-Volt Reference or I/P Dimming Voltage Reference		Depinned
13​	PU	Brake Pedal Switch Normally Closed Contact Signal		Depinned
14​	***	Not Used		Depinned
15​	***	Not Used		Depinned
16​	TN/BK	High Speed GMLAN Serial Data Bus +		Depinned
17​	TN	High Speed GMLAN Serial Data Bus -		Depinned
18​	YE	LED Backlight Dimmming Control		Depinned
19​	L-BU	Serial Data Communication Enable		Depinned
20​	***	Not Used		Depinned
21​	OG	Front Fog Lamp Switch Signal (T96)		Depinned
22​	L-GN/WH	Cruise Control Indicator Dimming Signal		Depinned
23​	***	Not Used		Depinned
24​	***	Not Used		Depinned
25​	PU/WH	Indicator Dimming Control		Depinned

 

[alia176]

@Scalpel what brand of aux fuel tank did you end up with and can we see pics? I bet this will help out others as well.

Thx.

 

[CanVanLX96]

@Scalpel thank you so much for your great work with detailing the swap process. This is one of the best documented process for swapping a V8. Thank you again. Your whole journey documented in such details is a quite an inspiration to me and my son; now we are feeling much more comfortable to start our own journey with a V8 swap in a 96 LX450. Now I'm very confident we will start our V8 swap in the spring time.
Thank you again.
All the best.

 

[Scalpel]

@Scalpel what brand of aux fuel tank did you end up with and can we see pics? I bet this will help out others as well.

Thx.

On the fuel tank... I wasn't as intentional about taking pictures of it. I used a tank from an Isuzu trooper and hung it in the back of the rig under the cargo area. I couldn't come to terms with the price of the Toyota fuel neck/filler that toggles between tanks so I made my own. Essentially used an exhaust Y-pipe that I saw laying on the ground at the junkyard that I thought would work. Welded a very short (1") of the Toyota fuel filler neck to it so the cap would still screw on. A little tricky to get the angle right but it wasn't bad.
I bought a dented landcruiser fuel tank from the junkyard. Filled it with water and cut out the area where the hanger bolts on. I made a similar hole in the Isuzu tank (removing the Isuzu hanger mounting plate/area) and welded the mounting plate and skirt from the Toyota tank to the Isuzu tank. (Let me know if that doesn't make sense and I'll try again.) This allowed me to keep the wiring all Toyota. The tanks area close enough in depth that the Toyota float did not need to be adjusted. Also had to cut a hole in the floor of the rear cargo area to access the hanger. Made a plate that bolted back on sealing it up.

 

[ButterManJones]

When Toyota designed this fuel delivery system, the pump was set up as kind of a 2-stage pump depending on the fuel demand. There are a few folks out there that have done an LS swap and retained the Toyota system. I'm not one of them. I wanted to make it much simpler and understand how it worked in the case I ever had to troubleshoot it.

Additionally, there are a handful of swap threads in which guys retained the original Landcruiser fuel pump. I had reservations about whether it could keep with the 6.2L engine so I went with an aftermarket pump. After I'd completed the swap, I plumbed a second fuel tank and just for the heck of it put the old LC fuel pump into it. With a switch, I can change the gauge, idiot light (for the fuel being too low), pump power and plumbing from one tank to the other. For what it's worth, the OEM Toyota fuel pump keeps up with this motor without any problems.

Would you say it's worth keeping the factory pump to avoid the extra work and cost then?

 

[Scalpel]

I could have kept the pump but I'd recommend rewiring it. I don't know how you'd wire the LS ECM to the Toyota wiring. The LS simply closes a relay to turn the pump on.

 

[alia176]

On the fuel tank... I wasn't as intentional about taking pictures of it. I used a tank from an Isuzu trooper and hung it in the back of the rig under the cargo area. I couldn't come to terms with the price of the Toyota fuel neck/filler that toggles between tanks so I made my own. Essentially used an exhaust Y-pipe that I saw laying on the ground at the junkyard that I thought would work. Welded a very short (1") of the Toyota fuel filler neck to it so the cap would still screw on. A little tricky to get the angle right but it wasn't bad. I'll edit this post later and add a couple pics. I bought a dented landcruiser fuel tank from the junkyard. Filled it with water and cut out the area where the hanger bolts on. I made a similar hole in the Isuzu tank (removing the Isuzu hanger mounting plate/area) and welded the mounting plate and skirt from the Toyota tank to the Isuzu tank. (Let me know if that doesn't make sense and I'll try again.) This allowed me to keep the wiring all Toyota. The tanks area close enough in depth that the Toyota float did not need to be adjusted. Also had to cut a hole in the floor of the rear cargo area to access the hanger. Made a plate that bolted back on sealing it up.

Cool, thx for that. I do belive the Trooper tank as an aux fuel tank has been approached before but I'm not sure if I've ever seen install pics. Anyway, I'll keep an eye out on this thread when you post up. This is one of those easy mods that folks can do if they really don't want to deal with jerry cans on the bumpers, roof rack or on the inside.

Did you end up using the fuel transfer ECU that George makes up for us? Shoot, can't quite recall his username at the moment but it's a slick little ECU that works well with the factory fuel transfer switch. Just a FYI.

Link to George's ECU

 

[Scalpel]

I'm going to go on a little tangent and go through the aux fuel system and then we'll get back to the swap. I did not set up the system for a transfer pump. I have a pump in each tank. I can switch the fuel pump, gauge and plumbing with a switch. The tank does come with a skid plate that fits pretty well. Some pics:

Filler Neck & cap removed (yes, that is JB weld I put over top of my welds on the vent. Wasn't sure those were air tight):

 

[Scalpel]

This is a pic from inside the wheel well looking out. You can see both filler neck hoses and one vent hose. This is also how the two filter/regulators ended up.

Up front they come into this:
Amazon product ASIN B005ETOVZM

And it's all run through this switch:
Amazon product ASIN B07MZ6CK34

 

[Scalpel]

Back to the swap... ALTERNATOR

Apparently, the Gen IV alternators are a little tricky to get to play nice. I didn't want to figure it all out so I swapped mine at the local wrecking yard for a Gen III from a 2003 Tahoe. It has the 4-pin connector. Only 2 of the pins get used (The two middle ones). The gen IV 2-pin alternator plug was depinned from the E38.

On the gen III alternator, the “I/F” wire is gray (Generator Field Duty Cycle Signal). The “L” wire is brown (Charge Indicator Control / Idiot Light). On the Toyota side, the black wire was followed under the fuse box and removed from a junction to another black wire. (Sorry that's so vague but if you work backwards from the plug from the 1FZFE alternator this is what you'll be working with.) The yellow/white wire was connected to the brown wire on the Gen III LS alternator and the black/blue went to the gray one.

Gen IV plug on the left and Gen III plug on the right

 

[Scalpel]

MOTOR MOUNTS

Started by cutting 4x6” plate from 3/16 stock (frame is 3/16 so I didn’t see a need to go thicker than that for mounts). Holes drilled into plates so they’d bolt to the block.

LC rubber was shot. Looked at using them with new rubber and discovered that OEM mounts are about $125 each. Change of direction… used polyurethane bushings and made my own.

Sourced polyurethane bushings (Energy Suspension 32124G 1-1/2” OD Rear Frame Shackle for Chevy Pickup)

Used 2” by ¼” thick strap for the dog ears and ¼” by 1 1/2” ID tubing. Used a burr to remove the seam on the inside of the tubing.

Prepping to fit the engine to the engine bay...

 

[Scalpel]

FIT THE ENGINE TO THE ENGINE BAY

HKR8051 manifolds work. They fit between the frame rails without any trouble

There is definitely a sweet spot in which the PS pump & AC compressor fit evenly spaced btw the frame rails. There is a tubular horizontal frame support that limits how low the engine can go. With about 3/8” to ½” clearance at each of these, the motor fits. Hood will clear and the truck intake cover can go on. The hood insulation touches the intake over when closed, but it’s not resting on it.

I would concur with the posts on IH8MUD that say the engine has to go forward and to the PS ¾” or so. The side to side movement is determined by the frame rail clearance. The forward movement is to get the PS head to clear the firewall. I did have to trim a corner off the PS heat shield (on the firewall) to keep the valve cover from touching.

Moved the trans mount forward and to the PS by 3/4'” each direction. Did this by drilling two new holes in the crossmember for the trans.

Motor put in and mounts tacked in place. Removed motor and burned them in. I went ahead and gusseted the mounts with 3/16” plate just because it makes me feel a little better about it.

 

[Scalpel]

The transfer case was a bit of a pain to remove from the trans while in the vehicle, so I bolted it to Mark’s adapter while out. Had to take a flap disk to the lower passenger side housing (of Mark’s adapter) as it bumped into the transfer case housing and would not allow the bolt hole to line up. (Should have taken a picture of this.) It took a couple of guys to line it all up but this was I could torque all the bolts.

 

[Scalpel]

TRANSFER CASE SHIFT
Because the transmission moved forward and to the PS side, I’ll needed to relocate the 4hi/low shift lever by that much.

The linkage had to be shortened. It was removed and cut in half. I removed about ¾” and welded it back together.

Using ¼” plate cut it to about 5”x5”. Drilled holes that correspond to the shift lever mounting holes. These will secure the plate to the adapter. Moved the shift lever rearward and to the DS ¾” each. Holes drilled and tapped to 8x1.25 to secure the shift lever to the new plate.

 

[Scalpel]

TRANSMISSION SHIFT LINKAGE

Bought shift linkage from 2005 Trail Blazer at the junkyard.

Shift arm on 6l80e was flipped upside down

Bracket was built to support the shift cable at the transmission

Fabricated support bracket for shift lever side of cable (to be mounted in the trans tunnel on the floorboard). I found that it’s very important that this ends up in exactly the right spot. For this reason, I slotted one of the holes to allow for adjustment prior to drilling the second hole.

Had to cut the shift lever arm (that goes through the floor) to shorten it and add the GM nipple to connect it to the shift cable.

 

[Scalpel]

Couple more pics of the shift lever. Not fully snapped in on the pic on the right but you get the idea.

Here is a pic of the shift lever cable support. It's mounted on the passenger side trans tunnel

Finally, I set the whole thing up on wood so I could work on shift gates and get and adjustment done. Glad I didn’t try to get this right with the tranny in.

When properly set up, the shift gates work with the LC gates. I haven't mentioned this yet as I assume it will come later but the '94 LC shifter does not have enough gates. The '92 does so I used a '92 shifter. Again, we'll get into this again later. I'll also explain the little red switches on the shifter in a bit.

I did pick up a shift cable boot (from the emergency brake of a wrecked FJ80) to cover the exposed rod as it will be under the body (was in cab in the Trailblazer). This boot will keep grit out of the shift cable, but it offers some resistance to putting it into low gear (The boot was a little too short or too long. I can't remember). Otherwise I wouldn’t know it’s there. Not too bothered by it.