Estimated reading time: 6 minutes.
If you’re thinking of tuning your 1HD-FTE Toyota Landcruiser with a Unichip, or maybe you’re looking to really turn the power up and throw a new UFI turbo on it, add high flow injectors, PDI intercooler, all the good stuff, but you’re wondering
Can the old girl even handle increasing the power?
Is it a silly idea?
Is 500,000KM’s too much?
Like most owners of the 1HD-FTE engine you want the best of the both worlds, a rugged reliable tourer, but also a bunch of grunt when you flex that big toe onto the loud pedal – and rightfully so, these engines are certainly famous for it.
I have some good news.
I am not here to crush your dreams.
In fact I’m here to tell you tell its entirely possible, even with 300HP+ packages fitted, the 1HD-FTE engines are barely breaking a sweat and continue to rack up hundreds of thousands of KM’s after being modified correctly.
It’s also not uncommon for us to pull apart engines with half a million KM’s or more, and find barely any wear to the pistons or rotating assembly.
Well, what’s the BUT?
Before you go turning up the power, there is some maintenance we would highly recommend doing to your engine whether its a stock HDJ79, HDJ100 Toyota Landcruiser, or a modified vehicle like an 80 Series or Nissan Patrol with a 1HD-FTE swapped in.
Intake Clean
Like most diesel engines, the intake manifold on these things get disgusting.
Especially if the car is completely stock with the original EGR system. Shit and crud builds up in the intake over time, restricting the airflow to the cylinders, and just generally making a mess.
Cleaning the manifold can’t be done properly with some spray in a can from your local auto store or any other outside method – the only way to do properly it is physically remove your intake manifold and scrub it clean.
Or stitch someone up who has access to a hot wash for engine parts nearby.
While we’re on the topic, it’s also a great time to put your intake back together with a fresh set of gaskets. They become soft and deteriorate over time causing a boost leak / oil leak from the manifold area.

The main consumable you’ll need for this job is a set of intake gaskets which can be found here.
Brand New Injectors
If your injectors are over 200,000km old and you’re on the fence about their condition, or you don’t have a history on them at all. Replace them – period.
This is one of the few problems we run into when dyno tuning the 1HD-FTE engine on customer vehicles. More than a few times we have had a vehicle that just will not make the kind of horsepower we are expecting. Assuming everything externally is working correctly, 9 times out of 10, a new set of injectors brings all the flavour back, and we hit those numbers bang on the head.
While it’s true that diesel injectors can last many hundreds of thousands of KM’s past their due date, old injectors are also unlikely to be spraying correctly, with a partly blocked nozzle or low pressure fuel being injected.

What do I need to replace the injectors❓
- Washer kit, seats, O-rings and return washers
- Rocker cover gasket
- Nozzle holder seals (These often get forgotten)
Injector Pump / Lines
We would recommend replacing the injector pump around the 400,000km mark. This is not a hard-and-fast rule but more than often than not, we hear from customers experiencing pump issues at around this amount of KM’s, and have seen it countless times in our own performance workshop. While a worn-out pump might carry on for a very long time, it can become quite obvious when we increase the power as we’re asking the pump to output more fuel.
Common signs of failure include,
- Low power – The 1HD-FTE suffers from low power if the injection pump is about to fail. It is an early sign of the above P1215 EDU Circuit Fault code, without actually turning the engine off or throwing an engine light.
- EDU Circuit Fault P1215 – When the engine shuts off around 2800RPM-3000RPM (depending on load), this is an indication that your injection pump has failed.
- Timing Control Valve Fault P1220 – It is common for the timing control valve to fail, this will cause an engine light and the engine to have varying amounts of power, and have a louder than usual engine noise from too much timing advance, or none at all if is on the retarded side of timing.
- Other General symptoms: Poor fuel economy, excessive smoke, ‘rev hanging’.

What do I replace with with?
The 1HD-FTE uses a electronically controlled diesel injection pump, it is well designed and reliable. The factory pump is capable of over 400hp+ with high flow injectors. So for 99% of our customers there is no upgrades or modifications we would recommend having done to your pump, nor would we recommend having it reconditioned.
We have found the rebuilt units pass fuel room testing, but may not suffice for performance upgrades. Just simply replace it with a brand new, genuine unit to keep the performance going for many years.
This Injector Pump is 100% suitable whether you have a HDJ79 or HDJ100 Toyota Landcruiser.
While you’re in there… it’s a must to replace your high pressure injector lines that run from the pump to the injectors if they’re looking a bit old or crusty. Here is a link to them.
Valve Clearances
At the kind of KM’s we’re needing to do maintenance on the 1HD-FTE, it’s not uncommon for the valve clearances to be slightly out and this is also a part of the recommended maintenance before we fit a performance package in our workshop. You’ll notice a lot more valvetrain noise from the 24-valve head when they are out of spec.

It’s a massive pain in the ass to do them on their own, so if you’ve already got the valve cover pulled off to replace injectors, this is the time to adjust the valve clearances back into spec and keep the idle smooth and quiet. They’re adjustable from the rocker arm and don’t need shims.
Some other pieces of maintenance that are worth mentioning:
- Radiator
The factory plastic top radiator is really well-designed and is the only way to go on your 1HD-FTE. But if it’s looking faded and aged on top, it’s time to swap it out for a new one. If we had a dollar for every time a car showed up here for a heap of performance work with a crusty old radiator, and we went “dude, really?”
What about a new mega thick aluminum high performance radiator?
Nope, aluminum radiators are too rigid and known for cracking on corrugated roads. There’s also no reason your 1HD-FTE should overheat with a factory radiator. OEM or the Koyorad replacement on our website is perfect. - Timing Belt
The 1HD-FTE is renowned for being one of the simplest timing belts to replace, with labour times often quoted at around 1 hour.
Here’s a link to our aftermarket timing belt kit, it contains a Gates Belt and Japanese components for high quality, and it only costs about half as much as the genuine kit. - Or, if you’re like me a love genuine parts, here’s a link for you to our genuine timing belt kit for the 1HD-FTE.
- Boost leaks
Check for crusty old pipes, leaks from the intake manifold, and blown off vac hoses. Especially the hose connecting the MAP sensor to boost. - MAP Filter
A cracked map sensor filter that is leaking air will cause a number of performance issues, because the MAP sensor is not reading correctly. This is one of the first we check before dyno tuning a vehicle in our workshop. MAP sensors are crucial to regulating fuel & boost on Toyota Diesel ECU’s.
If your plastic MAP sensor is cracked and leaking, we have new Stainless Steel Map Filters.
To summarise? It’s entirely true that you can tune your high KM 1HD-FTE regardless of age. These things were built to last even with performance upgrades. But fuel system maintenance is something you absolutely want to be on top of, to keep it happy for many years to come.
Going to overhaul the fuel system? We made it easy, as a complete package containing everything you need:
https://hdautomotive.com.au/product/complete-1hdfte-fuel-system-package/
What now?
Now that your engine is all freshened up, the best place to start is increasing the performance is by adding a Pre Tuned Unichip X. It’s the first step with adding any performance upgrade on these vehicles!
FAQ❓
Q: What size injectors should I replace mine with?
A: This is a really common question we get, because if you’re going to spend some coin replacing them you might as well upgrade right?
The most correct answer is to pick the size that actually suits your horsepower goal.
Standard Injectors
~220HP Max – Perfect if you’re happy with the power you can make with a Unichip/Turbo upgrade and don’t want to go further.
High Flow Injectors
~270HP (+17) – For 5 speed Auto Builds
~250-330HP (+30)
~350HP+ (+50, +70, +90)



