Ideas for improving the 2LTE (3 Viewers)

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GTSSportCoupe

2LTE abuser
Joined
Mar 23, 2012
Threads
237
Messages
9,078
Location
Victoria, BC, Canada
Updated February 23, 2016

I own an LJ78 Landcruiser Prado (2LTE), and I love it. These vehicles are very well built and generally as tough as other cruisers with the exception of the small IDI turbo diesel 2LTE engine. I feel they are one of the most undervalued and unappreciated cruisers out there. Fix the engine issues, and you have a winner. With the exception of the engine and rear axle the light duty cruiser shares almost all major parts with the heavy duty cruiser lineup (1990+ 70 series and 80 series).

I think everyone knows that these engines are prone to overheating under high load conditions leading to cracking the head between the intake/exhaust valves into the coolant passage directly above. Head failure usually occurs when steam pockets form in the coolant passages in the head. The steam pockets cause uneven temperatures in the head (hot spots). Uneven temperatures cause stresses in the head which lead to the metal cracking. Poor maintenance will accelerate the problem. To understand how to prevent overheating issues, we need to understand exactly what is happening that leads to the problem.

The Prado was marketed as a light duty luxury sub-urban SUV in Japan, thus it was given a small quiet engine and soft coil springs with luxurious interior options, while retaining many of the components from the heavy duty land cruiser lineup. The 2lte engine is an Indirect Injection Diesel. This means it has a pre-combustion chamber in the head. This design was used in smaller consumer vehicle engines as it reduced diesel knock noise, and increased the usable power band. The main disadvantage with this design is that it is thermally inefficient. A large amount of heat is lost through the pre-combustion chamber into the coolant passages in the head.

On non-turbo diesel engines, the IDI design works very successfully. The entire non turbo series of Toyota L engines (2L, 3L, 5L) are known to be very reliable and long lasting with no over heating problems; yet they share the same head design as the turbo engine!! When a turbo is added with the accompanying extra heat (compressing more air, burning more fuel), the IDI engine becomes seriously disadvantaged. It is not mere chance that Toyota's only two IDI turbo diesel truck engines (2LTE and 1KZTE) both have head cracking issues, while the DI (direction injection) turbo diesel engines (13BT, 12HT, 1HDT, 1KDT etc..) are known to be very reliable with no cracking problems.

Toyota further aggravated the 2LTE IDI problem by maintaining a very high compression ratio, adding an emissions system, adding an electronic injection system, neglecting to intercool the engine, and using a small undersized fan/shroud. All of which add even more heat to the system than is necessary. They then put this small displacement 95hp engine into a 2200kg vehicle with a slush box auto transmission.

Add to that poor maintenance by the original owners in Japan, and we have a perfect storm. One wonders how the little motor lasts even as long as it does!!

So how do we counteract this turbo diesel IDI heat problem? There are three ways, one use a waterless coolant that does not allow steam pockets to form. Two, reduce the heat being absorbed into the head/coolant in the first place. Three, increase the heat being removed from the coolant.

I have discovered the 2LTE can be made into a sufficiently reliable, cool and powerful engine with the right modifications and driving style. I have done many modifications on my engine (with good success), and have shared my notes/experience below.

Disclaimer: The following mods may not be for everyone. I'm just sharing my experiences with the 2LTE. Feel free to add your own ideas to this thread, or criticize what I've said. I'll add to this thread as I further mod my engine and discover new ideas.

Following is my recommendation to anyone that already owns a 2LTE and would like to improve it:

- Download and read the manuals!

- This is a Denso manual that explains in detail how the 2LTE electronic diesel works. It's an excellent read:

V 3 P5ZGR01.pdf

- These are the engine manuals for the L series engines. They do not cover the electronic injection system, but everything else is applicable to the 2LTE motor:

RM520E (Main for 2L, 3L & 5L engines)

Dropbox - 2L 3L 5L ENGINE RM520E.pdf

RM582E (Supplement for 2L, 2L-T, 3L and 5L engines)

https://www.dropbox.com/s/1joci2o0xtg6ujv/2L%2C2L-T%2C3L%2C5L ENGINE SUP. RM582E.pdf?dl=0

Finally, if it's a Prado you are working on, here is the manual that covers the rest of the vehicle (RM183E):

_KZJ70_HZJ_PZJ_chassis_body.pdf

This is a Youtube video that explains how the 2LTE injection system works:



- CHANGE TO A WATERLESS COOLANT!! I have done every modification below (except a turbo upgrade), and finally went to Evans High Performance Waterless Coolant in the Spring of 2015. I have to say, I am confident that this stuff is the ultimate protection against cracked heads in the 2LTE engines. If a person were to do NOTHING else (except basic maintenance), and only went to waterless coolant I have full confidence their cylinder head would never crack. The conversion will cost minimum $250 in coolant/flush agent alone, and is quite a bit of work. It is critical that all the old coolant/water be removed from the system for the waterless coolant to work correctly. I have put this stuff through the paces towing my 16' camper trailer and even running up to 240F coolant temps, and it works super well. I can't say enough about this stuff. Every 2LTE on earth should be running it. Note, your engine will run warmer with it, as Evans is not as efficient at transferring heat. This won't matter though, as the stuff does not turn to vapor until 380F!!! There are people on Mud that have run up to 270F on IDI engines (running Evans) with no ill effects!

- Install an EGT gauge immediately, and never allow post turbo EGT's to exceed 1000F. Drive accordingly. Always shift down on the hills to bring the rpms up. On the worst hills, keep the rpms between 3000-4000, and you'll see a big drop in EGTs. NEVER shut the engine off without proper cool down. Use your EGT guage and water temp to judge proper cool down time. Personally I let mine cool down to less than 400F post turbine on my EGT gauge, and ensure I'm at normal coolant temp before shutting the engine off. If really hot, turn the manual throttle control to 2000rpm to help the engine cool down faster. Generally after an easy drive this is a few seconds, after a really hard run it can be a few minutes.

- Buy and install a good quality aftermarket temp gauge. Never allow the engine to overheat (with regular water mix coolant). These engine will not tolerate being over heated. With the factory gauge, do not exceed the halfway mark. With an 82C thermostat, the gauge should be sitting around 1/4 normally. An 88C thermostat will put it around 1/3 normally.


- Bring all engine maintenance up to date:

- Oil change/filter,
- Fuel filter,
- Air filter,

- Coolant system service (pump, hoses, rad service if needed, new thermostat (82C), rad cap, new Toyota red coolant - or go to Evans High Performance Waterless Coolant as discussed above)
- Check clutch cooling fan for correct operation, replace it if necessary, or at least replace silicone oil in it. This is VERY VERY important. Check that the spring is intact. Open the unit, replace the fluid with 50ml of 10,000Cst Silicone oil, and test the turn on temperature. Blue fan clutch mod
- Add redline water wetter to your coolant (water based coolants). It reduces the chance of bubbles forming in the hot spots of the head. It's cheap, and may save your engine.
- New ECU coolant temp sensor

- Injector service if needed
- Injection pump repair if needed
- Timing belt job if needed
- New glow plugs if needed
- Turbo rebuild if it needed

- And of course make sure the rest of the vehicle is in good shape so as not to make the engine work any harder than it needs to (no dragging brakes, under inflated tires etc.)

- Do the free/cheap modifications first to reduce EGT's and improve power/efficiency:
- Remove the entire intake system from the turbo to the head and clean the sludge out of it. Also clean the sludge from the intake ports and valve stems in the head. Mine had 3/8" build up. The sludge is caused by emissions systems (EGR/PCV) dumping crap into the intake of the engine. The result of this sludge is that less air gets into the engine, making for a rich burn. A rich burn causes high EGT's, which in turn make for a hot/stressed head.

- Prevent future buildup of sludge by installing a PCV catch can, or just venting it under the vehicle (like the old cruisers did), and

- Remove the EGR system (all related pipes, VSVs, vacuum hoses), and fabricate/install block off plates at the exhaust and intake manifolds. Removing it will prevent sludge, but will also prevent hot exhaust gasses from feeding back into the intake.

- Remove the throttle plate in the venturi/throttle body. The throttle plate is there primarily to make the EGR system work. It also makes for slightly smoother idling and shutdown (again, a luxury thing) Removing the throttle plate will eliminate throttling losses, and thus allow better power at all throttle positions less than wide open. As it allows more air into the engine, EGTs will be reduced further. Throttle response and cold starting will be greatly improved. Do not remove or tamper with the throttle position sensor while doing this job!! (or it will need to be re-calibrated)

- Upgrade the undersized factory cooling fan with a larger one (such as the Toyota V6 'ring fan'). This will require a custom spacer or different fan clutch/hub to prevent the fan from interfering with the crank pulley and fan shroud. I have discovered that when Toyota shortened the front end design of the 70 series to the softer look of the Prado, they really screwed up the cooling and air flow capacity. There is not enough room for a proper shroud and fan. There is no where for the air to go behind the fan, as the engine sits too close. This I've found is one of the big mistakes of the Prado design.

- Upgrade to a high flow air filter. There is a K&N factory replacement filter available; not recommended for extreme dusty conditions though. However works perfect on highways. Allows more air into the turbo for cooler running and increased efficiency.

- Install an adjustable bleed valve on the vacuum line leading to the electronic boost sensor (there is a thread by pradocruzer on how to do this). The bleed off valve will trick the computer into thinking there is less boost than there really is, meaning there will be less fuel injected, and thus lower EGT's. Tune the bleed valve for good power and low EGT's. The tune of this valve will change depending on the work you do to your engine. Reducing 2lte egt's

- Increase the boost to 12psi using an Ebay manual boost controller. More air means lower EGT's. Don't turn the boost up beyond 12psi without an intercooler though, as the increased turbo heat will be negate any advantages of the increased air volume. With an intercooler, you can basically run as much boost as you want/can. I run 16psi, which seems to be about the max I can get with my setup.

- If auto, add a transmission cooler in-line before the radiator trans cooler.. This will reduce the amount of heat that the radiator has to dump. The trans oil will still need to run through the rad to maintain proper operating temp though (otherwise it would likely never get up to proper temp). The torque converter while out of lock-up will generate a substantial amount of heat which is transferred into the radiator. Once your engine is setup to make more power, you can stay in lock-up up hills and thus generate less heat.

- Run an 82C thermostat instead of an 88C. This will give a little more head room with engine coolant temps.

- For technically advanced owners, there are correction resistors on the fuel pump that effect injection timing and volume. Read the manual I posted above to understand how these work. I cut the wires for the resistors at my ECU, and installed my own adjustable resistors (potentiometers). I played around with this quite a bit, but in the end I found for my application that the factory resistors were actually the best values for power/temperature/efficiency. Don't advance the timing too much, or you will cause damaging diesel knock.

Do the expensive modifications to lower EGT's and improve power/efficiency:

Exhaust:
- Replace the entire exhaust system with a good quality free flow 2.5" or greater diameter system. I welded up my own aluminized mandrel piping with a Aeroturbine 2525xl, and it was a huge improvement.
- Buy or fabricate a dump pipe to remove the worst exhaust restriction which is at the output of the turbocharger. I have not done this yet, but did bore out my dump pipe which helped a lot.
- Better flowing exhaust/dump pipe lowers EGT's further. In my application, it dropped max EGTs by 150F

Intercooler:
- Install a front mount intercooler (more efficient than top mount). Pradocruzer demonstrates a highly efficient air/air front mount intercooler system which requires removal of the A/C. See post #6 here How to Install a Intercooler on a '91 Prado EX5 (2L-TE)?
I went with a water to air intercooler system so that I could retain my A/C. Here are details on my setup: LJ78 Air/water intercooler working! It dropped my EGTs by at least 250F max. This allowed me to crank up my boost and fuel all they way, and really transformed the power of the engine. It ran cooler and made at least 50% more power.

- Add a snorkel to gather cooler cleaner air near the top of the vehicle. This apparently can lower EGT's, and increase fuel economy. I have not yet done this, but will when funds permit.

- I have experimented with water/methanol progressive injection. In theory this can greatly reduce EGT's (water), and increase power (methanol). Some of the advanced kits only turn the system on at a pre-set EGT level, and then progressively increase injection volume with boost pressure. I installed a Devil's Own 250psi progressive system. Power was definitely up, but I have not seen the reduction in EGT's I was expecting. Perhaps I just need to play with it more. My 2LTE is an alcoholic

- Finally, if you have deep pockets, upgrade to a more efficient turbocharger as the factory unit produces a lot of heat at higher boost levels (as it moves outside of it’s efficiency range). A modern turbo from a 2.0l-3.0l displacement diesel engine would work well. Perhaps a Garrett GT2052 or similar. This will require custom fabrication etc.

- Tune the engine by way of the, boost controller, the spill control valve screw, and the boost sensor bleed valve. A final tune might be best done on a dyno. The above modifications will cool the engine down so much that it becomes possible to make significantly more power.

Feel free to post in this thread if you want more information on how to implement these modifications, and I'll try to answer your questions.

Here is my engine with pretty much all the mods listed above (except snorkel and new turbo) done to it. It is completely transformed from the lump I first bought. Unless towing I don't have to look at my gauges at all anymore. I can travel up 8% grades (often in OD) at 100km/h with my vehicle loaded with passengers/gear without high EGTs or water temps.

SAM_0069_zpslq9zglxt.jpg
 
Nice detailed "how to post". :beer:

It has been pretty well documented that the head design on this engine sucks. But yes, anything you can do to keep the heat down will make it less likely that you'll have vapor pockets forming. The other fix I have heard of is using Evan's Waterless Coolant. It requires a completely dry cooling system before adding. I do know that Crushers prepped his vehicles very well before they were allowed out the door. They still came back with blown heads. A friend has just fit a aftermarket head from the UK into one on his van. The design is supposed to take care of the overheating and the blown head issue.
 
Nice detailed "how to post". :beer:

It has been pretty well documented that the head design on this engine sucks. But yes, anything you can do to keep the heat down will make it less likely that you'll have vapor pockets forming. The other fix I have heard of is using Evan's Waterless Coolant. It requires a completely dry cooling system before adding. I do know that Crushers prepped his vehicles very well before they were allowed out the door. They still came back with blown heads. A friend has just fit a aftermarket head from the UK into one on his van. The design is supposed to take care of the overheating and the blown head issue.

I used an additive called "redline water wetter" in the coolant when I had my 1KZ-TE to combat any overheating/head cracking issues, it's fairly inexpensive and can be added to any coolant. On previous vehicles with OBD2 I was able to log the changes in operating temps under various circumstances, and it definitely makes a difference in engine coolant temp by way of allowing more efficient transfer of heat from the engine to the coolant, and from the coolant to the air passing through the rad.

Anything is better than nothing when you're dealing with this kind of thing IMO.
 
I have also been using Redlines WaterWetter since I changed the head. I use it because it lowers the surface tension in the coolant, which reduces hot spots on the head by not allowing vapor bubbles to form as easy (vapor obviously doesn't transfer heat like coolant does).

Does it reduce overall coolant temperature? I dont see how as it should be at a specific temperature anyways, its just makes it more effective at removing heat from the metal surface. I hardly ever see my coolant temperature rise more than 88C (192F). There were a few times where under heavy load for extended periods it would rise to about 205-210F. I remember this one logging road in BC we drove up the side of a mountain for 2.5 hours to get to the top. It was about +32C that day, and we had it pretty weighed down. Even pushing it hard, it wouldnt go any higher than 210F. The view was worth it though.

photo_zpscff8730e.jpg



I like the idea of Evans Coolant but two things made me not want to use it. One, it doesnt mix with anything else. On a road trip if you were to loose some coolant , you would need to flush it all out and go back to normal stuff (as its not available in many places). Its very very expensive so that would make me mad. The other thing that concerns me is its lower specific heat capacity. Water has the best cooling capacity as it can absorb the most heat per volume. Plain water is 4.2 J/kgK, but when its mixed 50/50 with ethylene glycol its about 3.7. Evans Coolant has a much lower heat capacity. When I was looking in the past I couldnt find a specific number. It means you need more of the coolant flowing over a certain spot to remove the same amount of heat.

One thing that I should add is that Evans coolant has such a high boiling point, you can run a pressure less system.
 
I think evans is about 10% worse than a 30/70 mix which I would run if I were you. One of the benifits of evans is it wont boil under even extremely high temps, so you dont have to pressurise the system. I had a rad hose with a tear in it and I didnt notice a leak until I squeszed it. Under normal operation it barely leaked at all. Unless a hose got riped off you would not have a catistrophic coolant leak, in which case it would suck. On long trips I bring and extra 2 jugs. Your system also will see almost no corrosion and the stuff lasts for decades without degrading and you can drink it and not die. I say you because Id never do that, but you could if you wanted to.

Water wetter is a great idea, but if you have low flow in a praticular area in the head, limiting egts and good coolant will be your best bet, unless there is a high flow water pump available for these motors. Id actually like a high flow pump but havent found one for the 3B. If you did replace the head with a new one, ceramic coating would be a great idea.

On a side note, where exactly do these heads crack anyhow? 3Bs crack inbetween the valves which is where, I suspect, the greatest disparity in temperatur occurs. Ceramic coating the intake runner would help as well to keep it as close to operating temps as possible. And the combustion surface as well.
 
2lte cracks between the valves. Here is a picture borrowed from the Surf forums:

a2b23f58.jpg
 
Great post. I will agree with the effectiveness of those mods. Although the head may crack eventually, it's running like a champ right now. Not underpowered either. Turns 33s with no problem. And runs as cool as could be.
 
God would I love to know why there is a halfmoon cut out between the valves. Why dont Toyota engineers ever come on forums and answer our design questions. :rolleyes:
 
What a great how to thread! It inspired me to action. I already did the EGR block but was a little leery to take out the whole EGR system and clean out the intake system. It all came apart pretty easy, cleaned up nicely, and went back together without a hitch, almost. I'm just not sure where this one vacuum line should connect.
495A9F85-502A-4FD3-B431-4AC88C8F91AF-466-000000219C97CCAB.jpg
[/IMG]

It's amazing all the extra parts that are leftover
C80B7199-7C97-4E02-8EE9-DA2F9CE726B8-466-0000001BB1822298.jpg
[/IMG]
Chad Wells

Sent from my iPhone using IH8MUDp
 
What a great how to thread! It inspired me to action. I already did the EGR block but was a little leery to take out the whole EGR system and clean out the intake system. It all came apart pretty easy, cleaned up nicely, and went back together without a hitch, almost. I'm just not sure where this one vacuum line should connect.

It's amazing all the extra parts that are leftover

Chad Wells

Hi Chad,

Nice work! I looked into it a bit further, and I think the vacuum line you speak of is the one which is a vacuum supply to all the EGR stuff you removed. So basically just trace the line back and cap it off at a convenient location.

Here is a picture of the vacuum system of the 2lte LJ78
2lteVacuum_zps22141f2d.jpg


Basically you will have removed everything in the picture except the vacuum line and filter that goes to the boost sensor.

As I mentioned in a message to you, I re-purposed the metal line over the top of my engine for use with my boost gauge which is why there is still vacuum line connected to it.

When you feel up to it, at least pull off your throttle body and remove the throttle plate. It'll make a huge difference to your engine. Just don't remove the throttle position sensor while you are at it, or it will need to be re-set with a feeler gauge (I don't even know the specs for this engine). You'll need to drill out the screws that hold the throttle plate to the throttle shaft, as they have a permanent lock compound holding them in.
 
I have also been using Redlines WaterWetter since I changed the head. I use it because it lowers the surface tension in the coolant, which reduces hot spots on the head by not allowing vapor bubbles to form as easy (vapor obviously doesn't transfer heat like coolant does).

Does it reduce overall coolant temperature? I dont see how as it should be at a specific temperature anyways, its just makes it more effective at removing heat from the metal surface. I hardly ever see my coolant temperature rise more than 88C (192F). There were a few times where under heavy load for extended periods it would rise to about 205-210F. I remember this one logging road in BC we drove up the side of a mountain for 2.5 hours to get to the top. It was about +32C that day, and we had it pretty weighed down. Even pushing it hard, it wouldnt go any higher than 210F. The view was worth it though.




I like the idea of Evans Coolant but two things made me not want to use it. One, it doesnt mix with anything else. On a road trip if you were to loose some coolant , you would need to flush it all out and go back to normal stuff (as its not available in many places). Its very very expensive so that would make me mad. The other thing that concerns me is its lower specific heat capacity. Water has the best cooling capacity as it can absorb the most heat per volume. Plain water is 4.2 J/kgK, but when its mixed 50/50 with ethylene glycol its about 3.7. Evans Coolant has a much lower heat capacity. When I was looking in the past I couldnt find a specific number. It means you need more of the coolant flowing over a certain spot to remove the same amount of heat.

One thing that I should add is that Evans coolant has such a high boiling point, you can run a pressure less system.

That looks like Fletcher Creek forest service road near woodbury by ainsworth. Am I correct??
 
Prize? Other side looking up ? Seriously good to see this type of stuff on here, thanks for sharing your knowledge,love the deletes .
 
I removed the throttle plate at the same time so all is complete. A upgraded turbo and gauges ( boost and EGT ) are on the way, they should be here by the end of the week. Power module and water to air intercooler before the end of the year.
Chad Wells

Sent from my iPhone using IH8MUDp
 
A fellow sent me a question by PM with regard to making block off plates for the EGR system. I thought I'd post my response here so that others can benefit also.

jeamer said:
Hey, your 2lte improvement post is very thorough, thanks for that. I've got a surf that I just swapped a 3L head in after the 2L head went on it (probably bought it that way). Anyways, one week in and I'm already looking at slowly implementing your recommendations to keep the 3L purring for a long time.

Did you fabricate the EGR blanking plates yourself? They look really thick (>5mm?), what did you cut them with? I wish we lived in the UK so I could just order them from the surfforums guy who laser cuts them and posts them out.

Anyways, thanks for all that info you posted, maybe I'll see your cruiser out and about and give a wave!

Hey, your welcome for the 2lte post!

Yes, I fabricated the block off plates myself. When I had the EGR stuff removed, I traced the intake manifold end out on a piece of aluminum, and traced the exhaust manifold end out on a piece of steel. I don't remember the exact thickness of material I used. Probably around a 1/4" thick. Fortunately for me there is a machine shop at my work, so I have access to a lot of material and equipment. Anyhow, I cut the pieces out on a band saw if I remember correct, and then I rounded the edges on a belt sander. I drilled holes in the pieces to match the original EGR flanges. I think I may have used shorter bolts/studs too.

A quick and dirty way to do all this is just cut your EGR pipes short, and cut out pieces of a tin can to match the size of the EGR pipe flanges. Punch holes in the tin can to match the bolt holes. Sandwich the tin can pieces between the EGR pipe flanges and the manifolds. Re-use the original gaskets if possible (especially at the exhaust hole), and use some high-temp silicone at the intake manifold hole. Re-use the original bolts/studs.
 
Thanks for that. I had thought of chopping the pipes and using the ends to bolt on blanking "gaskets" as you said above, I just liked the idea of a cleaner looking plate. There's a machine shop on campus where I work so maybe I can sneak in there...
 
- For technically advanced owners, there are correction resistors on the fuel pump that effect injection timing and volume. Read the manual I posted above to understand how these work. I cut the wires for the resistors at my ECU, and installed my own resistors (1/4W) to effectively advance the injection timing. Advancing injection timing lowers EGT's by promoting a more complete burn. The 2LTE's timing is retarded from factory to lower NoX emissions. Retarded timing means the fuel is still burning as it leaves the engine. This still burning fuel causes major heat issues in the area of the head that incidentally is the part that cracks. Don't advance the timing too much, or you will cause damaging diesel knock, and it may also cause the fuel to burn in the pre-combustion chambers, possibly causing them to crack. I advance the timing resistor two steps per the factory values and left the volume resistor stock.

Hay, what do you guys think, is this mod similar to putting a 'chip' in? The co in OZ that I ordered my upgraded turbo from say that have a tuner for 2lte. I'm just wondering how much tuning can be done safely without spending the $900.00 for a tuner? Have any of you put a tuner in? If so how much difference did you notice?

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Thanks for that. I had thought of chopping the pipes and using the ends to bolt on blanking "gaskets" as you said above, I just liked the idea of a cleaner looking plate. There's a machine shop on campus where I work so maybe I can sneak in there...

I see now you are in Sooke BC. What campus do you work at? I work at UVic and use the Physics machine shop there. The machinist who works at that shop lives in Sooke too, heh.

- For technically advanced owners, there are correction resistors on the fuel pump that effect injection timing and volume. Read the manual I posted above to understand how these work. I cut the wires for the resistors at my ECU, and installed my own resistors (1/4W) to effectively advance the injection timing. Advancing injection timing lowers EGT's by promoting a more complete burn. The 2LTE's timing is retarded from factory to lower NoX emissions. Retarded timing means the fuel is still burning as it leaves the engine. This still burning fuel causes major heat issues in the area of the head that incidentally is the part that cracks. Don't advance the timing too much, or you will cause damaging diesel knock, and it may also cause the fuel to burn in the pre-combustion chambers, possibly causing them to crack. I advance the timing resistor two steps per the factory values and left the volume resistor stock.

Hay, what do you guys think, is this mod similar to putting a 'chip' in? The co in OZ that I ordered my upgraded turbo from say that have a tuner for 2lte. I'm just wondering how much tuning can be done safely without spending the $900.00 for a tuner? Have any of you put a tuner in? If so how much difference did you notice?

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I would be very careful about buying a chip; in fact, personally I would not. Have a read through this to gain a bit more understanding of what you are dealing with: http://www.lcool.org/technical/elec_diesel_tuning/tuning.html It is a good article on diesel tuning of land cruisers.

Keep in mind too that very little development is being put into aftermarket for the unpopular and outdated 2lte engines. So whatever tune you end up with will likely have little thought put into it. Also, the 'chip' manufacturers are selling their product as providing more power, not making your engine last longer. The quick and dirty method to more power is more fuel, which means higher EGTs. Exactly the opposite of what you need for your 2lte right now.

I've messed around a fair amount with my 2lte, and I can confidently say the easiest and most productive method of tuning that will allow more boost (without hitting boost cut at 1bar/14.7psi) and reducing the over fueling nature of the 2lte, is to install the boost bleed valve that I mentioned in my first post. Pradocruzer on this forum developed this, and I must say it works very well. You just turn the knob until you get the best balance between EGTs and power. I got rid of my trail of black smoke under boost, lowered EGTs, and allowed the engine to boost higher if I want (plan on 16psi after intercooler).

After your intercooler and dump pipe/exhaust modifications, you can begin thinking about going high boost and adding more fuel. But you'd be tempting fate by doing this ahead of time. Also, Toyota specs a couple of ways to increase fuel in their injection pump calibration procedure. One is by way of the injection volume resistor, but the other way is by adjustment of the spill control valve screw. I think when I eventually adjust my volume up I'm going to use the screw.

Also, to further answer your question, I would not recommend you play with the injection pump resistors just yet. Some of the other methods of tuning will have a greater impact on your engine, and are worth playing with first. I have read that for some people the resistors made a really big difference, but it is likely that their pump resistors were out of spec to begin with. Have a read through this thread if you'd like to learn more about it. I personally feel these guys are pushing things WAY too much, and are doing damage to their engines. http://www.toyotasurf.asn.au/forum/viewtopic.php?t=29886&highlight=correction+resistor
 
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For what it's worth, I added a snorkel onto my truck with the 2LT-E.

My EGT's are consistently 75-100 degrees cooler.

1000 miles into it, I believe that the lowered EGTs and cooler intake air are amounting to a roughly 3/4MPG increase in mileage.

I should have installed the snorkel years ago, it's definitely helped the engine breathe significantly cooler air.

Dan
 
For what it's worth, I added a snorkel onto my truck with the 2LT-E.

My EGT's are consistently 75-100 degrees cooler.

1000 miles into it, I believe that the lowered EGTs and cooler intake air are amounting to a roughly 3/4MPG increase in mileage.

I should have installed the snorkel years ago, it's definitely helped the engine breathe significantly cooler air.

Dan

Can I quote you to my wife to justify the purchase of a snorkel for my LJ78? :D

Seriously though, that is pretty cool. Makes me pretty serious now about a snorkel.
 
Can I quote you to my wife to justify the purchase of a snorkel for my LJ78? :D

Seriously though, that is pretty cool. Makes me pretty serious now about a snorkel.

As much as you'd like. My wife was impressed.

Dan
 

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