1KZ-TE swapped Tacoma

Well I finally did it, I finished a project that took me four years start to finish: swapping a Toyota 1KZ-TE turbo diesel into my 2003 double cab.



My truck originally was a 3.4 automatic which was fine for a daily and the occasional trip to the mountains but it just wasn’t nearly as cool as being the only guy around with a diesel yota. The idea rattled around my head for a few months until I found a build thread from @anothernord and decided to do it myself instead of forking out $20,000 to have a shop do it. I started looking into the oil burners our overseas friends get to enjoy and found one for a decent price ($3,700 shipped back in 2020.)

Here’s how it arrived:


First thing I did was pull the glow plugs to make sure none dropped which I was told is a common issue with the kz motors. Number one had dropped the tip and left a small dimple in the top of the piston. Probably would have been fine to slap it back together, throw a new set of plugs in and call it good but I also noticed that all four pre-combustion chambers were cracked. So seeing how I had no history or mileage on it I decided to go ahead and rebuild the whole thing. I had the bores cleaned up and new valves, guides, precups, balance shaft bearings, and pistons installed by a local machine shop. I also had the injectors and injection pump rebuilt by Denso.

Between college and work my project was put on the back burner for a couple years until this summer when I got crackin’.

A few assembly pics after a fresh coat of paint:






Turned out that the factory turbo had a crack around the wastegate port and had also been spitting oil into both the housings then up into the intercooler so I opted for a new TDX series CT12B from GCG Turbos, figured getting a high flow couldn’t hurt as I’d like to push around 18-20psi eventually. $1,500 and a month later my little Aussie war whistle was ready.



In the meantime I pulled the V6 and transmission out and got the four banger set in:




I didn’t get a lot of pics of the rest of this so sorry about that.

Nice thing is the 1KZ uses the same motor mounts as the 5VZ on the frame side but needed different rubber insulators to fit the diesel mounts. The transmission crossmember had to be moved back about an inch and a half, simple job but a pain to get a grinder in there to cut the factory welds.

The transfer case that came attached to the manual tranny turned out to be an AWD case from a Land Cruiser Prado (the same one as the FJ Cruiser I think.)
It’s a lot longer than the Tacoma case and I like the classic J-shift so I ditched the Prado case and got a V6 manual one from Marketplace. After that I got my rear driveline cut and the front retubed to the correct length, then the clutch pedal and correct brake pedal installed.

The injection pump is capable of pulling fuel from the tank by itself so I deleted the lift pump and used the relay for the spill control valve. I used an OEM Toyota fuel filter and replaced the factory one with a few inches of rubber line.

The wiring turned out to be much simpler than I anticipated. Before this project I had never done anything with wiring and was pretty intimidated (electricity is black magic and not to be meddled with as we all know) but once I sat down with the diagrams for the Tacoma and the Prado I eventually got it all figured out.

Essentially the diesel harness needed to be extended by about 3ft to fit the factory ECU location and a handful of wires moved to different terminals/connectors. I hacked up the 5VZ harness for the spare wire and also so that I could retain the ADD harness. I picked up a Hilux fuse box from a junkyard in Australia and added the glow plug/starter relay box to the Tacoma fuse box. I moved the junction connector from the unused Hilux box to behind the gauge cluster and used it to tie the glow plug relay, spill valve relay, check engine light and the OBDI connector in to the ECU (RIP OBDII Diagnostics.) The tachometer was sorted out with a Dakota Digital signal converter tucked away under the dash.

The factory top mount intercooler was pretty beat up and would have required a hood scoop to work properly so I used a Mishimoto J-Line which fit quite nicely behind the factory bumper. I tipped it downward slightly to get as much airflow as possible without cutting the bumper.


To plumb the intercooler in I bought a cheap universal kit from Amazon then cut and welded it to fit. I also had to weld in a couple bungs for the air temp sensor and the MAP sensor.

I made sure to discard that pesky EGR valve and replace it with some block off plates, this also meant the vacuum line for it was no longer needed so I deleted the hardline and threw a cap on the barb coming off the vacuum pump.

For the exhaust I built a 3” straight pipe from the turbo back.

Here’s the very nearly finished engine bay:


So far I’ve put around 1,000 miles on it since the swap and can honestly say I will never forgive Toyota for not selling diesels here in the States. So far the only issues I’ve had have been a small leak from the crank seal on the timing gear cover and the tank filling slowly but I think the latter is a result of the filler neck diameter.

And here’s the obligatory startup video:
https://youtube.com/shorts/J-WXw3eEmyE?si=BJEEz86zLbRHiZ2s

 

very cool!

 

Holy crap
Beautiful !!!!!

Q’s:
-motor mounts?
-this ADM diesel engine….
Year?
DEF or pre DEF?
High Pressure FP?
Mechanical FP?
Where did u mount water separator filter?

looks fantastic
Great work and persistence!!!!!!!!!!

 

Uses the same mounts as the v6 with different isolators

JDM engine, got it from an importer in Florida I think

not sure about the year I think it’s a 96-00

pre def

no high pressure pump just a line from the injection pump to the tank

The injection pump is kinda funky by USDM standards, it’s basically a mechanical fuel pump with an ECU controlling it

 

Yep!
You got a runner there!
That ‘funky’ MFP…….
As long as working properly, 1000 times better than the $120k king ranch type HP pumps

if you’re getting “weirdness” with fuel delivery/mileage/lack of power
Check out some Mercedes forums for reputable companies that completely rebuild those units for less than $1k
(Those 1980’s 300D models that run 500k miles for half life)

Oh yeah……water separator (fuel filter)?

 

The Toyota fuel filter has a water separator I just haven’t gotten around to wiring in the warning.

Eventually I probably will put a new lift pump in but she’s running like a dream for now.

 

Spectacular!

im guessing here….
That MFP is on the driver side of engine I think. Is it here:
??

 

Yep that’s it right there. Heres the backside of it

 

Oh wow
Trying to figure out
I’m correct saying that MFP is cam driven by a belt???



Thanks btw
Love new stuff like this

In NO WAY am I contesting u!
Cheers

 

Actually the pump is driven by the timing gears and then the pump drives the camshaft through the timing belt.

here’s the repair manual if you’re interested

 

I love everything about this thread... What part of Oregon are you from?

 

Pendleton area originally but in Eugene now

 

Bad to the bone, one of the coolest projects I've seen on here

 

How does this feel in comparison to the truck when it had the 5vz? Just more torque lower in the rev range? Any issues with it being slow to get up to highway speeds?

 

It has lot more low end torque but I’ve also noticed it’s much easier to accelerate at highway and freeway speeds even in 5th. It doesn’t like hills so dropping a gear or two to keep EGTs down happens a lot when climbing but overall it’s just so much better.

For comparison I have an Old Man Emu lift with 10 ply 285/75r16s and 4.10 gears. The lift and tires really bogged down the v6 especially on the highway and now it feels like it has more get up and go than the v6 did before those mods

 

Hell yeah dude! DIY gang all day!

 

Awesome project! Do your cluster gauges all work?
What about heat and AC?

 

Yep everything works

 

freakin bullet proof!!!!!

 

piece of art IMO




thanks for sharing!!!!!!!!