Ok, I get so many emails concerning this subject that I thought it appropriate to take the time to right up a little FAQ on toyota diesels and converting USA/Canada trucks.
Q: Which years were they originally available in the USA/Canada?
A: The toyota trucks were available in 2wd for in 1981-1986. The engines themselves changed but they all share a similar design (IDI inline 4cylinder). You could get the 4wd models in 1985-86 in a turbo diesel form (2L-T). Although some of these 4wd versions I have seen with a 2L non turbo.
Q: What are the engines that were available with these trucks?
A: There were 3 truck diesel engines available here in the states.
1L-the first diesel engine available here in the US. A slow but rugged engine. It only was available NA
2L- A larger displacement 2.2L overhead cam inline 4 cylinder. A little better power than the 1L but no powerhouse.
2L-T- A turbo charged version of the 2L which in later models featured a roller rocker valve train and lower compression to compensate for the extra heat created by forced induction. The final version available from Toyota sold here in the USA and Canada.
Q: Are parts hard to find for these engines?
A: Not too bad. Some stuff can be found at NAPA and dealerships. It really depends what you are looking for. Some parts are no longer available so finding them requires a creative thinker. Since Toyota built these things in a modular fashion, most parts can be had from your local dealership. It helps to find the part number in the Toyota EPC here:
Q: I want to convert my USA/Canada truck to diesel. What engine/combo is the easiest to convert and cheapest?
A: All three engines share the same bolt pattern. So you can really use any of them.
Q: What is the ideal truck to convert?
A: 4x4 trucks/4runners from 1985-1995 with the 22re gas engine and w56 transmission should bolt right up. The electrical will be a little more involved but nothing too difficult. You will need the diesel motor mounts though for the V6 vehicles. The V6 powered vehicles are much more involved as they require torching off the frame engine mounts and reallocating them to use the diesel engine's mounts. There is alot involved including driveshaft mods and cutting off the old engine mounts and welding in new ones. Much more involved process and frankly, when using the 2LT engines is not worth the paltry power output you'd get. Another issue with the 2LT is that parts are getting pretty scarce so I normally dont recommend doing a conversion using this engine.
Q: Which transmission should I use for my conversion?
A: The w56 transmission is what you will need for any L series toyota diesel conversion. This is a 5-speed overdrive 4x4 transmission with a removable bellhousing. You will need to purchase a diesel bellhousing and swap out the gas bellhousing for the diesel one in order to mate the engine trans up sucessfully. The reason for this is that on the 22re the starter is on the passenger's side of the car. On the diesel, the starter is on the driver's side of the car. If you were to try and get around this, the turbo would basically be touching the starter and it wouldn't fit. The W56 was standard on 4x4 trucks and 4 runners from 1985-1995.
Q: Which engine would you recommend from your experiences?
A: The 1L and the 2L are not really worth the time. They are painfully slow and in a 4x4 setting, they are greatly underpowered. Pretty good for a little 2wd truck though. To convert a 2wd truck just buy the 2wd diesel trans complete with bellhousing and install. There are 3 more engine available only in Europe that are highly recommended for anyone doing a diesel conversion. They are:
2L-TE- Same block as the 2L and 2L-T but has an electronically controlled timing advance module in the injection pump which gives is much better response time under load. It controls mroe finely the fuel delivery and has a larger advance curve giving it a slight Hp increase of 10hp from the 2LT. The bad news with this engine is that; due to a casting flaw from Toyota, they are highly prone to cracking between the exhaust valves requiring a replacement head. Toyota issued a TSB (technical service bulletin) regarding the casting issue and ultimately redesigned the head with a new casting to alleviate the problem with cracking. The new cylinder casting is identical to the cylinder heads used on the 3L engines and can be purchased through Toyota USA for approx $600 usd. This coupled with the fact that they are not exactly powerhouses make them a suitable but not ideal candidate for conversion. Additionally, wiring is comparable to a 1kzte conversion.
3L- A 2.8 liter sharing the same block as the 2L and 2L-T/2L-TE. A manually controlled injection pump so they are not too complicated to wire up. Since they are not turbocharged, they are not as powerful as the 2LTE's but for a small 2WD truck, they're great.
1KZTE- Toyota went back to the drawing board in 1992 and came up with the K series diesel engines. This engine block shares very little with the L series diesel engines. The displacement is 3.0 liters (2996 cc) and has very good hp/torque output. People have put them into 89-95 trucks, 4runners, Tacomas as well as Tundra's with excellent results. The big drawback on these are that they are computer-controlled so they require professional-level wiring in most cases and should be purchased in a half cut form to ensure that you get all associated wiring, transmission, and computer.
1KD-FTV-Toyotas evolution with the 1KZ platform. The 1KD engines are 16 valve (4 valves per cylinder) DOHC with a 3.0 liter displacement. The 1KD engines also feature Toyota's D-4D high pressure common rail fuel system with 32 bit ECU. These engines are fuel-sipping rocket ships compared to the 1KZ and perform more like gas engines! The issue with converting your truck using the 1KD engines is that Toyota also developed a highly sophisticated immobilizer system which is integrated into the vehicle ECU's. This immobilizer system makes installation for most people completely impractical. The only way we have found to get around this is to purchase a $24,000 Toyota EU dealer programming machine. This machine allows us to program all vehicle computers with the encrypted codes in order to have them all talk to each other and allow the truck to start. Many people think "well if I just get a half cut with a key etc.", but this approach will not work either. All 1KD ECU's use volatile EEPROM memory chips to store their immobilizer coding. This means that when power is cut from the ECU for any period of time, the ECU will default back to the "locked" setting requiring the programming machine.
Q:What is a half cut?
A: Taken from www.Dieseltoys.com "A "Half Cut" (aka front clip) is a complete vehicle purchased at auction in Japan which is cut in half in order to save space in a large oceanic shipping container. These vehicles consist of a complete running/driving vehicle without the rear half quite literally. All half cuts include the engine, transmission, computer, all associated wiring and gauges, fuel system, and cooling system. Half cuts range in price from $6000-$7000 depending on year model"
Q:How difficult are these things to wire up?
A: Depends on which engine you're dealing with. For the 1L. 2L. 2LT's, and 3L's there is really one wire to hook up for the fuel cut solenoid. This basically allows fuel to reach the inector lines. Wiring up the temp sending unit etc requires a bit of reading but nothing too difficult. The 2LTe's and 1kzte's are heavily computer controlled. They require professional-level of electrical skill in most cases. These engines are almost exclusively available in RHD (right hand drive) form so the engine harness must (in addition to rewiring) be lengthened to the passenger's side of the vehicle so they enter the firewall in the correct location. The 1KD engines are extremely complicated to wire up often taking weeks of 8 hour days in order to properly wire as everything is electrically controlled and use a drive-by-wire throttle system for the accelerator pedal.
Q: Where can I get a diesel engine for cheap?
A: I would highly suggest you not just buy the engine. You should always go for the half cuts which can be found on the internet. Jarco inc (www.jarco.com) used to import half cuts but no longer does so half cuts have become a challenge to find. Most JDM importers dont import diesels so it's been hit or miss for awhile in finding a diesel half cut.
Q:What all needs to be swapped out with my gas truck if I were to buy a half cut?
A:You will need to take out the following:
I'm sure theres more but if these dont deter you then go ahead.
Q: My truck has the stock sr5 guages with tachometer.How do I get my tachometer to work as diesels dont have an electronic ignition system?
A: There is a company called Dakota digital (www.dakotadigital.com) that sells a tachomter interface for diesel engines called SG-5 for around $85. The kit consists of a magnetic pickup and a basic receiver which is programmed by using a binary variable circuit board. Which means that you give it different settings for your desired output. You mount the magnetic pickup on the bellhousing facing the flywheel and take the number of teeth on the flywheel and look up the number on the chart and enter in the settings. This will ensure you tachometer is accurate.
note: All toyota guages use a high output signal to power their tachometers. Dakota digital's tachometer SG-5 kit sends a low output signal. You will need to tell Dakota digital when ordering the SG-5 that you need the SG-5 with a high output signal. All they do is combing the SG-% with the SG-8 (another interface they sell).
Q: I cant get my a/c system to cycle on and off like it should. It was working fine before the conversion. What's the problem?
A: All toyota trucks and 4 runners from 1990-1995 use what's called an a/c amplifier. This basically is a logic circuit that takes 3 different signals and then decides if your system is ready to operate.
1 signal is the tachometer signal. Even if the truck is not equipped with a factory tachometer, it still gets this signal from the factory. This tells the a/c amp that the engine is running. Then it needs an idle up signal which it basically sends a +12v to increase the engine RPM. To use this feature, you can use an idle up solenoid from an 85-88 celica or truck with te 22re engine. it's got 2 wires, 1 12v and other is ground. When energised is pulls and not, it retracts.Last is the switch in the dash. This is the sending unit which sends the power to the a/c amp which tells it to turn on. If you have all of these signals, your a/c will function flawlessly. This info took me 2 months of reading schematics to learn.
Q: there's not much info regarding Toyota diesels on the internet. Where is a good place to start reading?
A: Right here as well as http://www.toyotasurf.asn.au/forum/ which is an Australian Toyota board. Very helpful bunch over there!
If you have any other questions that are not convered in this FAQ feel free to PM me through this board. I will help in any way I can. Todd