Cooling the 1KZ-TE motor:

[johnkzn185]

Well for me its a choice between black smoke on start up and a temperature gauge that never moves , or less smoke and a temperature gauge that will climb when i push hard on long motorway journeys hence the fuel remains turned up . I need to move the manifold pressure and air intake temperature sensors up to the retro fitted intercooler which may have something to do with it .

so your having issues with the engine not coming up to temp? wouldn't you think that's a cooling system issue more than a fuel one?

 

[johnkzn185]

oops.. read that wrong sorry. do you have a EGT gauge? Has the fuel pump timing etc. been checked?

An added intercooler should be giving you a cooler charge air and lower egt's if all is good. What boost pressure are you running?

Would definatly look into a aftermarket dump pipe as well, take full advantage of your larger system. The stock dump pipe is not doing you any favours.

 

[Shayne]

I have a full 3" exhaust from the turbo back John , i've fitted a cooler from a Prado 90 and i use a K&N air filter . As a result i've spent plenty of time tweeking fueling which is a case of turning the grub screw and going for a spin . I honestly didn't think my factory temp gauge worked until during a 4-5 hour motorway journey ended with a mad dash in top gear at about 3700rpm for 10 or 15 minutes which made the temp needle lift about 1mm above its usual position . This made me curious so i've since turned fuel down a touch more just to test Beau's theory and as a result the temp gauge lifted at 70mph . So i've turned it up again and the gauge never moves beyond its usual point . On the bright side i'm now confident my factory gauge does work and my cooling system is adequate because when the gauge did rise i eased back to 2500rpm and the needle dropped to where it should be in less than a minute .

As for how it runs otherwise i can only offer that a 10 year old BMW turbo diesel saloon car i borrowed felt severely under powered by comparison .

 

[johnkzn185]

Sorry, from a comment before I thought you had a 3" system but hadn't changed the dump pipe. My bad.

The stock temp gauge is shocking, it is resistored from factory so it does not fluctuate or move around as much as what your coolant temps may. Run a aftermarket temp gauge and you'll see it isn't accurate at all. The stock needle wont move until you are already running hot, way to slow to do anything about it.
There's quite a large write up some where on the Aus surf forums regarding this. Even though that's in a surf, I would be prity confident in saying all the gauges across the models would be the same.


As much as I like fiddling with things, there is no way I would go playing with the fuel on a diesel unless I had a EGT meter. I've got one ready to go on, and now I have the manifold out of the car I can drill and tap a thread for it above the turbo flange for pre turbo egt temp readings. I wouldn't use my coolant temp gauge as a idea to adjust fuel with.

In my mr2's I run a wideband 02 set-up so I can see my a/f ratio.

I would seriously think about getting a decent EGT meter to see what your exhaust temps are really doing. But that's your decision.

 

[Beau]

Well for me its a choice between black smoke on start up and a temperature gauge that never moves , or less smoke and a temperature gauge that will climb when i push hard on long motorway journeys hence the fuel remains turned up . I need to move the manifold pressure and air intake temperature sensors up to the retro fitted intercooler which may have something to do with it .

Shayne, I had the exact same findings when I was doing testing with my fueling. Hence why I believed the leaner the mixture the hotter things got. When the mixture is then backed off from the lean side, I saw temperatures and EGT were better than standard operating temps like what you have found out. Seems to be a lot of controversy on this story, but I'll stick to my findings for now as they've proved well when pushing my truck!

 

[Shayne]

I don't know anything about physics but it seems logical to me that more fuel means a bigger bang resulting in more heat and it's sound in theory . But in practice less bang means the engine is working harder needing more revs to give lesser results which means more friction and more heat . Maybe that explains the controversy ?

 

[Towpack]

Depends how you define 'working harder'. Lugging the engine at low revs with a boot full of throttle is certainly putting more strain on the engine, especially the bottom end. Changing down a gear or 2 and running higher revs at the same road speed means less load on the engine, the water and oil pumps are spinning faster so cooling and oil pressure will be better/higher and because the engine isn't working as hard you can invariably ease off on the throttle slightly and maintain the same speed. JMO

 

[johnkzn185]

Defiantly weird findings. Goes against everything I've learnt about diesels. Just a few links that could be interesting reading.

https://www.dieselnet.com/tech/diesel_comb.php

http://www.dpchip.com/home/diesel-tuning-and-air-fuel-ratios-afrs/

http://www.berrimadiesel.com/home/smoke-signals/

http://www.bankspower.com/techarticles/show/25-Why-EGT-is-Important

 

[Beno]

From what I have seen with the black Art of tuning with a EGT gauge the AFR is the critical thing. Yes you run it richer and it will get hotter from what have seen using a EGT gauge. Drop it back a gear meaning more Revs but the temps will drop as you have dropped the load factor via the gearbox ratio. I previously had a 1HZ with a aftermarket turbo fitted. Fuel economy was approx 12.5 litres per 100 klms an the highway unloaded with 33 inch tyres and a 2 inch lift.

I never had any smoke from exhaust even under load. I ran a EGT gauge and watching it increase when going up a hill was unbelievable and around 500 deg c I would change back of a gear to stop it going higher. My EGT gauge thermocouple was post turbo. There is a train of thought that having the thermocouple mounted pre turbo gives you a more precise reading and that post turbo you have already lost approx 150 deg c in temp.

I also had a Tm2 engine coolant Digital readout which was far more reliable for engine temps. Lastly I had an extra 18 ml of viscous oil added to the fan clutch which also helped with cooling on a hot day.

Air Fuel Ratio is critical no doubt about that and also making sure your injectors are giving correct Atomization of fuel is just as critical. Lastly the timing of the injector pump is just as critical.if the timing is not right fuel is delivered to early or late and less bang for your buck but also possibly higher temps.

 

[Shayne]

The links John offers certainly give pause for thought

IIRC i fitted the 3" exhaust first which sort of freed the engine , it's hard to explain but anyone who has ever de-restricted a 2 stroke bike will have a fair idea of what i mean . This gave far more grunt and much less engine braking but i felt the truck ran out of power long before it should , revs would keep climbing without much effect on the speedo .

I then added the IC and the problem got worse changing up a gear at 2500rpm was mandatory even in top gear , so i turned up the fuel and it improved things somewhat but i still felt something wasn't right . So i swapped the air filter for a K&N high flow and bingo . I'm tired of telling the mrs who drives everything else like a little old lady that i would much prefer it if she would change gear before hitting 4000rpm !

Still the info in the links do alarm me . Timing belt was changed and injectors checked by mr T shortly before i started modifying , every 6 months or so i chuck a bottle of Wynns diesel gold injector and fuel system cleaner in the tank .

I have never seen my temperature gauge move more than 1mm above its usual spot and it only does that only long journeys which include a spell of speeds over 70 , and even then it only happens when i've turned the fuel down so start up smoke doesn't blacken my trailer which i park next to (side exit exhaust) . With the fuel turned up shes still pulling at 100 and no temperature issues though for obvious reasons that was a short test .

Does it sound like i have fuel delivery problems ?

 

[johnkzn185]

Think I would definatly be getting things checked out mate. Fitting a EGT gauge would be a good idea as well.

 

[johnkzn185]

Yea Beno, I drive my old turbo motorhome by the pyro. lower the temp, better my fuel economy as well.

 

[Towpack]

The links John offers certainly give pause for thought

IIRC i fitted the 3" exhaust first which sort of freed the engine , it's hard to explain but anyone who has ever de-restricted a 2 stroke bike will have a fair idea of what i mean . This gave far more grunt and much less engine braking but i felt the truck ran out of power long before it should , revs would keep climbing without much effect on the speedo .

I then added the IC and the problem got worse changing up a gear at 2500rpm was mandatory even in top gear , so i turned up the fuel and it improved things somewhat but i still felt something wasn't right . So i swapped the air filter for a K&N high flow and bingo . I'm tired of telling the mrs who drives everything else like a little old lady that i would much prefer it if she would change gear before hitting 4000rpm !

Still the info in the links do alarm me . Timing belt was changed and injectors checked by mr T shortly before i started modifying , every 6 months or so i chuck a bottle of Wynns diesel gold injector and fuel system cleaner in the tank .

I have never seen my temperature gauge move more than 1mm above its usual spot and it only does that only long journeys which include a spell of speeds over 70 , and even then it only happens when i've turned the fuel down so start up smoke doesn't blacken my trailer which i park next to (side exit exhaust) . With the fuel turned up shes still pulling at 100 and no temperature issues though for obvious reasons that was a short test .

Does it sound like i have fuel delivery problems ?

I'm Not that familiar with the IP on the 90 series but on the 80 series the pump has 4 separate fuelling adjustments that can be 'tweaked'.

1. The off boost fuelling......adusting this can get the turbo spooling up earlier due to increased exhaust gas fow.

2. The boost compensator profile..........governs the fuelling at low to mid RPM's

3. The Boost compensator characteristic tendency..eh?..........controls the amont of fuel injected at low to moderate boost

4. The main injection volume control which dictates the amount of fuel at max boost and rpm for full power but will have some effect across the whole range.

I'm guessing that when you say you've turned up the fuelling you mean the main volume screw?
If the pump on the you're engine has similar adjustments then it may benefit from some additional tweaking. I guess having several separate adjustments can make things more complex but does make the thing more fine tuneable.
Many would say an EGT gauge is not only useful but essential when playing around with pump settings and I'd be inclined to agree with them. EGT's can go dangerously high very quickly, long before the engine's coolant temp has had time to climb.
Temp drop across a turbo can be as high as 200deg. Monitoring the temp pre-turbo is better IMO as it's the temp closest to the head and pistons and it's these that'll suffer if the EGT goes too high.
It's ironic that for all the years a ran the Disco which had no EGT or oil pressure gauges I never gave either of them a thought, even when towing up big hills at motorways speed but then again the thing was completely stock and 'un-tweaked'!
JMO

 

[Shayne]

1kz-te += Electric pump so upping the volume is my only option as far as i'm aware , damned if i do and damned if i don't . I have wondered if a tuning chip set up on a rolling road is the answer to even distribution throughout the rev range ?

 

[Towpack]

1kz-te += Electric pump so upping the volume is my only option as far as i'm aware , damned if i do and damned if i don't . I have wondered if a tuning chip set up on a rolling road is the answer to even distribution throughout the rev range ?

If it's electronically controlled then it's a different ball game really. The 'fine tuning' is done by the electronics using data from the various sensors round the engine. I've never had a car new enough to have electronic injection but the last several bikes I've owned have been. The electronics can compensate to some degree for any modifications you may do the the engine, exhaust etc but only within certain parameters. Anything outside those parameters usually requires a re-flash or reprogram/remap of the ECU so I guess a re-chip and rolling road setup could be your answer. Electronic control certainly takes fine tuning to a new level but I just find it a bit annoying personally when you have to pay someone to do the electrickery for you when previously you could just get out the spanners and DIY!. JMO

 

[username_11]

Username_11, Thanks for the feedback. I generally hate doing this but I also hate to let things go ignored. If you read my post properly as well as other post in this section you'll read that what me and others have mentioned is not the fact that "thermostats" being used is unique. But the fact it's fed bottom to top. Does that make sense? If not, have a little search on google and it may help you understand better.

Lastly, that last point was more of a opinion based on what I've read on the internet, and testings I've actually done. If you have a look online you'll be surprised what you can learn. But hay, you don't have to believe me. It's not like I've stripped every bolt off these engine multiple times and rebuilt them or anything, over the past 16 years of owning a cruiser!

are you always such an condescending arse ? i said a thermostat controlling the flow of water into an engine is not uncommon, or as you put it fed bottom to top lol google it you'll find out why they are put there

i'll just agree to disagree on more fuel makes a diesel run hotter because what you stat goes against any diesel tuning i've seen

 

[Beau]

1kz-te += Electric pump so upping the volume is my only option as far as i'm aware , damned if i do and damned if i don't . I have wondered if a tuning chip set up on a rolling road is the answer to even distribution throughout the rev range ?

Some people have messed around with the resistor settings on the pump to get more of a fine tune, but this is way out of my league. However I know it's possible to fine tune the fueling. On top of this, with the right computer Geek and rolling road, you can re-flash your ECU (it has been done before) and you'll get even better results.

However, best bang for buck will be to simply get a mechanical pump and you'll have similar adjustments to what Towpack mentioned. And like I've mentioned elsewhere, I've seen guys run high HP and torque numbers with these pumps!

 

[username_11]

.......... That stock dump pipe does look horrid!........

i found with the 4runner (kzn130) set up, horrid dump pipe arrangement. the exhaust side is restrictive over 3000 rpm, need some more fiddling time to make and change dump pipe tho to see if it's dump pipe or turbo

......Another thing that I have seen discussed on a couple other forums is inlet design. Is there an issue of unequal air flow to all cylinder? Can that cause an issue? I'm sure that the Toyota engineers are the full bottle when it comes to designing and building their engines, but not always are they designed for the intended use of towing etc. more so than meeting ever stricter emission controls...

yeah i've seen it mentioned before, and toyota did change the inlet manifold on later higher powered engines. they have a bulge in manifold. i wonder if this was to even flow ?

 

[Shayne]

I've looked at it from every angle Beau and decided it's pointless to do anything until i get around to moving those sensors . As far as i can tell the ecu is set to adjust fueling in accordance with whatever readings it receives so given these trucks might end up in Mexico or Mongolia they must have a pretty vast scope for self adjustment .

 

[Rich Sims]

Right then , this is just my thery on why we get issues with the 1kzte heating.

It seam to me that these engine are one of the fastest heating up engines on the road and working at say 88 degrees the cooling system cant resond quick enough. First the thermostat has to open to start circulation through the rad which then has to reach around 95 degrees to then start heataing the bimotalic coil on the fan hub and if you have enough oil in will hopefully lock up and start cooling the engine!
Now none of this happens as quick as these engine can produce heat so sudden hill climbs or starting off from cold towing heavy loads will cause a massive heat spike before the cooling system can resond to keeping the temp under control!

The thermostat being at the bottom of the engine means that the top of the engine can be 5 degrees hotter, also those with auto boxes with the cooler in the bottom of the rad have another issue that when the thermostat does open there could be water in the bottom of the rad already at high temperature!

To make matter worst when towing on steep hills under 50 the gearbox will produce a huge amount of heat upto 200 degrees which it flows through the bottom of the rad rad where the engine is sucking water into the engine trying to cool it down!

My way of hopefully trying to combat the problem was to move the transmission oil cooler under the vehicle with a fan as putting a seperate cooler in front of the rad doesnt help and fitter an alloysport radiator, I also fitted a 71 degrees high flow thermostat which was listed for these engines in Aus then adjusted the fan to lock up around 88. I also took out the butterfies from the intake which restrict airflow massively at low throttle postions and threw the egr valve as far as i could throw it.

So over the last year of towing bloody horseboxes and towing a trailer around the pyrenees mountains up and down passes Ive never got the temp above 90 degrees which i think is alot better than normally teasing the 100 -110 mark.