2UZ Swap info

[Zjohnsonua]

This is NOT a thread to compare the UZ to the LS or any other platform. Hundreds of those already exist, carry on those discussions elsewhere, please.

Many threads exist in Mud asking about what's involved in swapping Toyota's 4.7L V8, the 2UZ-FE, but few of us that have done them chime in to help the decisions for the next guy, and the threads quickly become messy. Let's see about changing that. There are a handful of builds already in here that I'll add for reference.

I will not remember everything off the top of my head, so please ask questions and help construct this thread! Here's some general information that I share with people regarding this project to get things going:

- Toyota doesn't change interfaces often for critical parts, especially inside of a platform. Toyota is like Legos. Keep this in mind as you move through your project and are looking for a solution. (e.g. UZ oil filter mounts - I've seen 6 IIRC - pick the one that best suits your application - LS430 works well)

- Use the LC/LX oil pan/baffle/pickup assembly. Either get one from a core engine or buy them new (roughly $800 as of this writing). There are a couple pan options that you'll look at and think "I can make that work" - they're compromises - I discourage you from taking those routes.

- Many donor trucks came with immobilizer circuits. Some did not. The immobilizer can be removed - these guys perform the service. I recommend keeping the circuit as it's easy to work with so long as you get the immobilizer ECU, which if you buy a donor, you'll already have. No more worrying about your old Toyota being hi-jacked, just take the key with you.

- Buy a donor. The small parts you can get from them add up in a hurry. All the clamps, brackets, hardware, wire...this stuff adds up. and the OE stuff is WAY better than anything from the aftermarket.

- Use a 4th gen 4R fuel pump. They're affordable, widely available, and fit the factory drop in. You need to use something like S13025 (oreilly PN for reference) for a strainer. Needs to be 7/16" port with a side feed to clear properly. There are two 4th gen pumps, one has 1/8" terminals, the other has 1/4"...get the matching connector and go.

- The wiring is no worse than other platforms, it's just different. And it's less documented. We'll see about changing that here.

- As you clip away circuits, make sure and tie every ground from the ECU to the body, preferably in the same grouping that the EWD shows. Clean your grounds before installation.

- 1st gen Sequoia's air tube fits the best for most applications. 4th gen 4Runner's airbox stacks well, too.

- The A750 transmission shifts much smoother if it maintains a 180-190ish oil temp. You want to use a radiator with trans oil cooling. You also want a trans cooler ahead of the radiator oil flow path.

- You need a LC/LX transmission (either A343F or A750F, for most US readers) if you intend to use an LC case. This is because the LC cases (HF2A/HF2AV) require a longer trans output shaft.

- The A750 comes in several PN variants, main changes are the output shaft, tail housing, and an additional clutch/steel in some models. The scaries like sensors and switches swap over.

- The A343 comes in several variants, too. toojayzee did an excellent write up on this.

- Electric or mechanical fans - that's your call. Mech fans clear with no issue in both 60 and 80 series, even with the large clutch from the 100-series. You'll need to build a shroud obviously. I ran electrics for a bit and ran too warm for my comfort in ambients over 110F with AC running. Mech fan deleted this problem.

- 2wd or 4wd donor? They both offer perks. 2wd wiring is simpler as the 4wd circuit is absent. You'll enable 4wd with an ON/OFF switch of your choosing to control the CDL ECU and the engine ECU will be none the wiser. 4wd ECUs enable less abrupt shifting when in 4wd.

- Driveshafts and crossmember? I would plan on changing both. You'll end up with a better final product.

- A750 came with two shifter types, cable or linkage. Cable came on 4R and GX. I prefer cable as it's more compact and lets me put the shifter exactly where I want it. You need to change the detent arm in the transmission if you use a cable shifter on an LC trans.

FJ40 swaps: here's one from @UZJ40 and here's another from @Bripars40.

FJ60 swaps: My 60 is the only one that I know of a thread for.

80 swaps: @toojayzee listed above and Skitz's are good starting points

Please add other threads if you know of them.

These are broad strokes. Contribute, and we'll keep the thread going.

 

[Zjohnsonua]

Engine mounts...we used to use a cut-down Toyota chassis-side engine mount for the 100, but that's been NLA'd. We make them in house now. Feel free to reach out.

 

[CruiserDave]

I appreciate you taking the time to post this. Hopefully it will make this swap more mainstream and easier for the diy types.

 

[Bripars40]

Thanks for posting @Zjohnsonua

I’ll try and add some more helpful tips this week. There’s a few things I’m going to redo on mine in the next 12 months so I’ll try and update my thread with those as well.

 

[UZJ40]

Nice thread!!! Great info and very accurate.

 

[Zjohnsonua]

"The wiring is awful." Or something like that. False.

If you want the easy button, call Tim at Lexus V8s, they're also the guys that delete immobilizer if you elect so. Their pricing is on par with the LS guys and they're just as quick. Usually less than 2 weeks turnaround.

Or make your own by trimming down your donor's harness - this was the route taken on my 60. Some donors lend to this better than others. Sequoia, Tundra, 4R are the simplest speaking generally.

Or dig in and make your own harness altogether.

 

[Skitz]

<deleted>

 

[Skitz]

@LexusV8 Engines

Good thread for any input regarding the wiring/ecu services you provide.

 

[Stuckinthe80s]

Thanks for posting this! A couple of notes from my swap...

I'm going to caveat this with some of these notes are from the standpoint of doing what I had to do to get it through the tech inspection required for emissions here in CO. I couldn't have any codes, so things like using the fuel pump ECU and mounting/wiring up the EVAP system isn't necessary if you don't have to deal with that headache.

• Ditto on getting a donor vehicle to work from, especially if you are having to make it emissions compliant. My swap was pretty much as easy as it gets because I used an entire drivetrain from an early 100 series. After getting everything in place, the only linkage I had to modify was the rod going from the transfer case shifter to the case.
• I used a 100 series fuel pump. I mated up to the sending unit just fine, but I had to add bulkhead studs to run a negative back to the fuel pump ECU and used these to do so: https://www.radiumauto.com/Electrical-Bulkhead-Stud-Kit-6-Pack-P1049.aspx
• Can't reiterate enough about making sure everything is grounded properly.
• If I had it to do all over again, I'd probably buy a standalone harness for the power. I spent a lot of time on the stock 80 dash harness thinning it out and re-pinning the "D" and "E" connectors so it could seamlessly integrate in to the ECM. It looks factory, and I'm proud of it, but DEAR GOD did it take a lot of time. Mostly because I have ADHD and would walk away from it after a few hours. I wouldn't go back to it for a week or so and would have to spend a while figuring out where I was.
• Ditto on the wiring not being hard, it's just time consuming. This swap is impossible without a good EWD for the year you're trying to make everything work for. To clarify this, the wiring from year to year is almost always different, even within the same model. For a company known for efficiency, it doesn't make sense to me why they changed the schematic so much. It will be little things too, like the MRL wire being in the pin D5 location one year, and in D6 the next. ( I just made that up to convey my point) To summarize all of this, get an EWD for the model year of the ECM and another one for the model year of the vehicle the engine is going into.
• Ditto on the 4runner air box. It's a really nice fit in 80 series engine bay. I'll eventually make something to integrate into the 80 series air box, but the 4runner air box had all the vacuum ports for emissions stuff. I tried first gen Sequoia/Tundra air boxes as well as those from GS400, SC400, LS400, and everything else that had a UZ motor in it and nothing seemed to fit as well as the 4runner box.
• On my setup, I used a gauge cluster from a 97 and re-pinned the connectors accordingly. In the late model 80 series and the early model 100 series, the speed signal comes from the VSS, goes to the speedometer, the signal is conditioned, and then sent to the ECU.
• Speaking of the gauge cluster, everything on it works just like it was factory. The one thing that was weird is the oil level light comes on even though the early 2UZ doesn't have a sensor for this (that I can tell). I'll have to look back through my notes to remember which wire this is, but it is somewhat moot. I have put around 10k miles on it so far, with several multi-hour trips with no issues, so I just pulled the bulb, lol.
• If you decide to use a factory cluster on an 80, there is a potentiometer on the back of the tachometer that you can use to adjust it for the extra two cylinders. I couldn't get it exact across the entire powerband, but it's spot-on from 2k to 3k rpm, which is where I'm mostly concerned about.

I'll post more as stuff comes to me.

 

[Stuckinthe80s]

I should have noted this from the start....

@Zjohnsonua, @Skitz, and @UZJ40 were all super cool and super helpful with this when I was first getting going. Thanks guys for putting up with all my questions! This thread is going to help a lot of future projects!

 

[Stuckinthe80s]

Some more items:

• Exhaust: If you get everything lined up right (subjective term) there should be enough room to use stock manifolds and keep the flange on the drivers side. I lobbed mine off and v-banded it, but it wasn't necessary. For the passenger side, I did a v-band as well so that I could route it like FZJ
• 
  
• I didn't like the idea of the exhaust so close to the transfer case and the ref at the emissions tech center told me that the cats need to be in the relatively same distance away from the engine as the donor vehicle. Remember kids, my swap is basically CARB compliant. The rules that went into place in Colorado in January of 2022 made things a bit more stringent here in the front range, so I had to do this.
• I didn't mention this, but thought I might. The transfer case shifter from a late 80 bolted right up to the transmission from the 100. This should be obvious since it's the same transmission, but I thought I'd put it out there. The shifters themselves are different, but when you use the 80 series one, it puts it right where it needs to be.

 

[SHIfTHEAD]

I was having a conversation about this very topic this past weekend. I was told that the 2UZ would drop right in and mate to the existing transmission in my 97 LX450. I just wanted to confirm this is the case? Seems logical as early LX/LC's would have had the same 4 speed, right?

 

[Zjohnsonua]

I was having a conversation about this very topic this past weekend. I was told that the 2UZ would drop right in and mate to the existing transmission in my 97 LX450. I just wanted to confirm this is the case? Seems logical as early LX/LC's would have had the same 4 speed, right?

The UZ bolts up to the 343, yes. You'll need to swap your FZ bh out for one from an LC100/LX470/Tun/Seq.

Check out toojayzee's thread referenced above - he talks through doing exactly what you're asking.

 

[thepinktaco]

Getting ready to start the swap. 06 VVTi with A750. Been mapping out the wiring. Was hoping I could make T-harnesses for the connections to help make these swaps easier. 90% of the wiring is straight forward, the rest I’m still ironing out to make it operate seamlessly.

 

[Skitz]

Here's a summary of the major changes between years when looking at 100 series for your swap. I feel Tundras/Sequoias/4Runners followed the same year changes or maybe off a year


100 Series Changes by Year:

1998

• 4.7L V8 2UZ-FE Motor
• 4 speed Transmission – A343F

2003

• The A750F 5 speed automatic transmission was added
• Changed to a drive by wire with an accelerator position sensor on the accelerator pedal
• Engine HP slight Output increased
• Crank Hold Feature was added. This feature will keep the starter engaged, once the ignition switch is turned to the START position without having to keep the key in the START position.

2004

• SLLC (Super Long Life Coolant) accepted and service interval increased. The color of this coolant is pink
• The transmission dipstick was removed. The fill position is now checked at the overflow plug.
• ATF-W (Automatic Transmission Fluid) is now specified instead of the ATF-T-IV. The ATF WS is not interchangeable with other types of ATF (ATF type T-IV, or D-II).

2006

• 2UZ-FE Engine- The VVT-i (Variable Valve Timing-intelligent), ACIS (Acoustic Control Induction System), and AI (Air Injection) system are added to the 2UZ-FE engine to achieve a greater performance level and reduce exhaust emissions.

 

[Zjohnsonua]

To clarify, all 2UZs are fundamentally DBW.

Early models use a cable to actuate the APPS (accelerator pedal position sensor) on the throttle body (no way that confuses any one...), and the ECU uses that sensor data to control the TB. The cable's mechanism will engage the throttle blade from ~85%-100% pedal travel to enable limp mode. In other words, this allows a maximum 15% throttle actuation in case of throttle motor failure. These throttle body assemblies can be pricey - although some components are available independently.

2003+ got an electronic pedal and a smaller Bosch TB. These later model TBs are proving themselves to be more durable and are more widely available in service channels. When they need to be replaced, they're ~1/2 the price of the earlier assemblies.

For those taking non-LC/LX donors, the Secondary AI was introduced somewhere in '05 for Tun/Seq/4R, variations exist inside of lineups. It's readily deleted with affordable products from a few companies. Hewitt has been used with success.

SAI engines use different exhaust manifolds which enable the SAI system. If you're deleting the system, ditch the SAI manifolds for some from pre-SAI engines as they'll take up less room in the engine bay.

 

[Zjohnsonua]

When swapping the 4.7, you can swap the engine, or you can swap the whole system:

The difference between the A343F and the A750F is worth more than a note here. You can look up their sheets to get more familiar.

80 owners have a simpler, more affordable path to entry as the UZ bolts to the 343 with a bell housing change. The transmission logic is effectively the same between the UZ and the FZ. Threads listed above speak to other differences and how to resolve them.

Moving to the A750F buys smoother shifts between gear ratios that keep the UZ in a more enjoyable part of its power curve. Some of the included logic is handy too as it includes a nice downshift brake feature. If you plan to wheel your swap, some of this cost up buys a deeper 1st gear which mitigates the need for lower transfer gears. I've got a set of 3.1:1s on the shelf that I never installed - and I just don't see the need for - even on super technical stuff. The 750 is the easier of the two to rehome from LC/LX to a non-LC/LX donor ECU. It's controlled by a 2wd ECU perfectly well - everything plugs up. Discerning drivers may note that shifts in low range are more harsh, most won't. Be mindful of what type of shifter your donor used - there are detent springs on the valve body that are matched to the shifter - swap these over if you change something (literally one bolt is involved here).

The transmissions themselves are very similar between LC/LX and general trucks. . All LC/LX 343 and 750 transmissions are specific to this application due to the HF2A(V) transfer case.

 

[Skitz]

I own a 100 with a 4 spd tranny and my 80 has the 5 spd...

Everyday and twice on Sunday, I would take the 5 spd.... It does everything Zach said above...

BUT I also don't hate the 4 spd. It works fine and gets the job done.... so if you can find a 5 spd, there's good benefits... but a 4 spd is still a good option!

 

[Stuckinthe80s]

To keep beating the drum on differences between the 4 and 5 speeds....

I have the 4 speed and I don't think I needed to "massage" the trans tunnel to make room for the center diff lock actuator. i mean, I did, preemptively because I saw it in almost every thread. However, after I got everything in place, I don't think it was necessary. I'm assuming there is a length difference between the two.

And ditto with regards to the 5 speed being better offroad. Engine braking isn't great in low range with the 4 speed and I feel like that's the most drastic difference between the two. However, on road....meh. I get 17mpg on the highway and the in town driving experience is negligible compared to a Hundy with the 5 speed. I'm not saying the 5 speed isn't a better option, I just don't know if it's worth the extra coin. YMMV. Whichever transmission you go with, I can PROMISE you the 2UZ makes driving an 80 series SOOOO much more enjoyable compared to the straight sixes.

 

[Stuckinthe80s]

To clarify, all 2UZs are fundamentally DBW.

Early models use a cable to actuate the APPS (accelerator pedal position sensor) on the throttle body (no way that confuses any one...), and the ECU uses that sensor data to control the TB. The cable's mechanism will engage the throttle blade from ~85%-100% pedal travel to enable limp mode. In other words, this allows a maximum 15% throttle actuation in case of throttle motor failure. These throttle body assemblies can be pricey - although some components are available independently.

2003+ got an electronic pedal and a smaller Bosch TB. These later model TBs are proving themselves to be more durable and are more widely available in service channels. When they need to be replaced, they're ~1/2 the price of the earlier assemblies.

For those taking non-LC/LX donors, the Secondary AI was introduced somewhere in '05 for Tun/Seq/4R, variations exist inside of lineups. It's readily deleted with affordable products from a few companies. Hewitt has been used with success.

SAI engines use different exhaust manifolds which enable the SAI system. If you're deleting the system, ditch the SAI manifolds for some from pre-SAI engines as they'll take up less room in the engine bay.

Here is a diagram to show folks what you're talking about:

And the way I personally know what you're saying is true is because I forgot to put a fuse into where I was feeding power to this circuit and I the acceleration really sucked. I was getting pretty freaked out thinking I did something wrong then remembered that I forgot to put the 15A fuse in to give power to +BM

It still let me run it and drive it, but it was basically putting it into limp mode because there was no power to the throttle control motor, that is actuated with the accelerator cable.