Build 1991 FJ80 - The Long Game | Build Thread | 1UZ Swap

[bowtech4life]

Purchased for $3,700 as a rolling ’91 FJ80 chassis with body and interior — no engine or transmission installed. The sale included most of what was needed for a 1UZ swap, which so far has proven accurate.
The chassis is solid and complete enough to justify doing this correctly.

Objective​

Build a reliable, very capable 80 that can drive to and from the trail, wheel hard, and support camping use without compromising drivability. Focus is durability, serviceability, and long-term ownership.

Phase 1 – Roadworthy Foundation​

• Non-VVTi 1UZ from a 1997 Lexus LS400
• A30-43LE transmission out of who knows what
• Stock axles
• Mild lift (~2”)
• Clean wiring and plumbing

Primary goal: get it driving, sort systems, and enjoy it.

Phase 2 – Suspension & Drivetrain Evolution​

• Linked suspension
• Coilovers
• 38” tires
• Regear to match tire size
• Upgrade axles
• ARB air lockers

This stage will focus on increasing capability while maintaining highway manners and reliability.
The goal is to build it in stages, enjoy it along the way, and refine it over time. This thread will document decisions, execution, and lessons learned.

 

[bowtech4life]

Mistake #1....not checking if the engine turned before I bought the bundle. Not sure this would have mattered much since $3700 felt like a bargain anyway.

I had purchased a timing kit, F/R main seals, F/R head seals & half moons, gaskets, starter, alternator, sent the injectors to a rebuild shop out of Kansas to get rebuilt etc. etc. all to install before the install of the engine.

Long story short, I broke the keyway on the driver side camshaft trying to turn the engine to TDC. I removed the valve cover to find a rust mess. That didn't stop me, my local junk yard had a 1997 LS400 that I went and inspected, pulled oil pan to check for coolant and oil mixture and look for red flags on the crank and bearings, valve covers to inspect the valves and cams, inspected pistons with a bore camera, made sure it turned and everything. I couldn't see a reason why this car was sent to the junkyard so I pulled the engine and paid the $550 for it.

Don't worry, I have no clue if it runs and that's been living rent free in my head since I've been doing the project...stay tuned Forgive my use of explicit language on the starter. I can't imagine doing a starter job on one of these in the engine bay.

Junkyard pull:

 

[bowtech4life]

Once I got the motor removed from the junkyard car, I observed the starter to be in complete disarray so I assume that that is why the car ended up in the junkyard. Also, you never know what you're going to get at a junkyard. I discovered a broken off piece of aluminum behind the front crank cover and found it to be for a water pump housing bolt hole. Luckily it isn't one that the water pump seals to. I JB welded it back in place, gave it 48 hours to cure and then drilled and retaped the hole. Good as new!

 

[bowtech4life]

Oil Pan Swap
The bundle came with a mid-sump pickup, pan and "sub pan" is what i'm going to call it (its the piece that bolts to the bottom of the block). This is from an early SC400 non-VVTI 1UZ. This was necessary to clear the front axle and the steering. Unfortunately i've just got pictures of the front sump set up and a picture of the SC400 mid sump pick up.

 

[bowtech4life]

After this, I finished up installing everything else, seals, timing kit, etc. then moved on to the main engine wiring harness refab. The connectors are all extremely brittle and a nearly 20 year old harnesses tape and loom looks like trash. I heavily relied on CartuneNZ's videos on how to go about doing this so credit to him but essential its the following:

- Adhesive/sealing heat shrink
- PET braided sleeving (assortment of diameters)
- Tesa PET cloth tape
- Silicone tape where needed
- Zip ties
- Regular electrical tape

Maintain a good diagram of where each color goes into what pin (the back of toyota connectors usually will label the first pin with a "1" then you count each pin in the direction away from the 1). I also made a list of connectors that needed to be replaced. Part numbers found on the back of the connectors. Be prepared to spend well over $600 on connectors from Toyota if you do all of them. It isn't a very exciting task but it is very well worth the outcome as your harness will look so good. Follow CartuneNZ videos. He's an expert.

 

[bowtech4life]

Engine Mounts
After the wiring mess, I moved on to begin installing the engine mounts. This was the most intimidating part for me so far as all of my experience from the only engine swap I've ever done was a 5VZFE swap into a manual '93 PU that had a 3VZE in it so the engine mounts lined right up. Instead of fabbing up my own mounts I decided to purchase some from McKinnon's Cruisers out of Australia. I had prayers that the stock mounts would be close but they were a far cry from close so I broke out the grinder and cut off wheel and went to work.

I also unbolted the steering gear box and brake lines to give me more room to work.

This task can be done solo but its a pain. What I found to be the easiest solution was to use a motorcycle jack with a 2x6 across the arms to rest the transfer case on. The hoist has the engine way up in the air (like 6') then you rest the t case on the motorcycle jack and slowly lower the hoist and the tcase jack acts as a support off the floor and because it is on wheels, it rolls backwards as the engine is lowered.

After about what seemed like 1,000 iterations of that in and out, I finally was able to come to a final welding spot for the fishplates and frame mounts. The pro's on here will cringe at my welds but they penetrated and I wasn't observing any cold lap so I'm running it. I used POR-15 Topcoat to paint everything. I used a little bit of child labor to help prep the welds before paint

 

[bowtech4life]

Engine Mounts (cont'd)

 

[bowtech4life]

Engine fitment/clearance's/exhaust manifolds

Now that the mounts are done and I've got an idea of what kind of clearance issues I'll be facing

- Stock 1UZ LS400 manifolds: Driver side hits steering shaft, swap with 2000-2004 Tundra 2UZ-FE manifolds

- Whole drivetrain is ~10" forward resulting in transmission mount not lining up so a new crossmember will need to be fabricated
- Since drive train is 10" forward, trans and tcase linkages will need to be extended
- Custom drivelines?
This is showing the transmission mount in front of the skid plate/crossmember

The picture below is attempting to show the distance from the drain plug on the T-case to the drain plug hole for the skid plate/crossmember.

 

[bowtech4life]

Exhaust Manifolds + Exhaust plan
I found a pair of 2UZ manifolds brand new factory Toyota on market place for $300 for the pair. They provided much better clearance.

Exhaust plan:

• Use all 304 stainless steel exhaust components
• ER309L 0.030" filler wire
• Cut off factory 3-stud flange from manifolds (2" outlet) and replace with a vband, transition off the 2" outlet with an adapter to 2.25", weld vband onto 2" side of adapter/transition, weld a 6", 2.25" in/out flex joint onto 2.25" adapter side, down pipe down into a 2-1 collector with a 3" single outlet, 3" vband to a 3" in/out resonator, 3" to a borla pro xs muffler then finish.

Here is what i've got so far:

I have never welded stainless before so I am still working on fine tuning. My welder is a Titanium Unlimited 140 running 75/25 gas.

As you can see, the driver side manifold was cut above the O2 bung to provide the ability to clock the outlet away from the frame since it was pointing directly on top of the frame.

Vbands were installed to provide ease of removal of the down pipes and collector when the need to drop the transmission arises. I will stop exhaust fabbing at this point and transition to fuel line installation and crossmember fabrication

 

[bowtech4life]

Neutral Safety Switch + Trans fluid temp wiring
My A343F was missing the Neutral/Park safety switch (NSSU)....not knowing what the PN is for the A343F's NSSU, I went to my junkyard and sourced a NSSU off of a A341 (stock auto trans from LS400). This way the connector from the engine harness plugs right in. This is a shot in the dark as I don't know the differences between the A341 vs A343F trans NSSU's but we're gonna find out if it works. Bolts and linkages all lined up and it slid on the shift shaft of the A343F just fine.

The 1UZ's A341 shift solenoid connector (driver side dump) is also where the ATF fluid temp sensor wire goes to. I've identified what pin it is (yellow wire i'm holding in the pic below) and now need to move it over to the passenger side "in line" trans temp sensor. It just needs the one wire from the solenoid connector (your positive) and a ground. You'll need to run a wire for this and tie it into whatever is used for a ground for the solenoid connector (brown in the connector I'm holding below, chase it up the loom so that it comes off cleanly then make your splice near where you'll run it to the passenger side).

I found a compatible 2-pin connector off of the old '91 harness that came with the truck so I just reused it. Same pin type and everything.

 

[bowtech4life]

Transmission Solenoid Wiring (trans side):
I found out through studying my EWD's that this model transmission only needs S1, S2 and a Ground to shift and only (1) VSS (vehicle speed sensor). The LS400 has SLU+, SLU-, SLTN+, SLT- and an O/D clutch speed sensor that isn't used for this application. Luckily, this purchase came with all of the harnesses from both donors and an extra harness from somewhere . I wanted to keep the factory wiring color for the solenoid connector since that is what came with the transmission (for troubleshooting later) so I cut the A343F's solenoid connector from the harness, Identified my wiring and function (Pin 1 is Red = Ground "E1". Pin 2 Red/Light blue = S2. Pin 3 Red/Yellow = S1) then spliced them with adhesive lined heat shrink into my 1UZ's S1, S2 & E1.

The above gray connector is the VSS (vehicle speed sensor). The 1UZ has (2) speed sensors in that single grey connector and the A343F only needs the one (not the O/D speed sensor). I matched up diagrams and just popped the pins from the 1UZ's connector and installed them into the 2-pin connector, loomed and plugged it in.

 

[bowtech4life]

For transfer case function, that hasn't been documented yet. But all you will do there is run the FJ's pigtail that goes from the dash harness, through the firewall and to the engine bay connector that comes from the t-case harness. Cut/splice/repin whatever to work with the 1UZ body connector plug. A post will come for that eventually but that gets you up to speed to right now.

In the works right now: fuel lines, trans lines, crossmember fab and exhaust fab. Will document and post here with updates and snags.

 

[Rdonahe]

Nice work! Will be following along.

 

[bowtech4life]

Thanks @Rdonahe ! not sure if there is any way to make the pictures smaller as it makes it really difficult to make out the thread text but I'll figure that out too. I picked this project up not too far from you (Carson, WA) just across the river.

 

[RedGreen]

Great write-up. I will be following along as I'm starting a very similar project soon. I will have lots of questions as I get started.

 

[bowtech4life]

Thank you @RedGreen ! Appreciate it

 

[ddjohan]

Nice, local to me too. Looking forward to the project running.

Looks like mine, no flares.

 

[Rdonahe]

not sure if there is any way to make the pictures smaller as it makes it really difficult to make out the thread

When you attach the pic you should be able to click on it and resize smaller manually by dragging the edges. That's what I do anyway.

 

[NeverFinis]

Thanks @Rdonahe ! not sure if there is any way to make the pictures smaller as it makes it really difficult to make out the thread text but I'll figure that out too. I picked this project up not too far from you (Carson, WA) just across the river.

As suggest, one can just resize by dragging a corner. One can select the image properties and set a specific pixel width. Change from "Auto" for the width to "500px"

 

[bowtech4life]

I’ll make adjustments to picture size here once I’m at my laptop.

But has anyone converted their rod transmission shifter linkage to cable? I ask because the shifter arm that comes down from the inside of the truck is impeding my ability to raise the drivetrain up higher.