1KZ-TE / KZJ78 Mods (1 Viewer)

[Slowcruiser]

Hi all, first time reaching out, appreciate this forum, has helped me out a lot so far. I have a KZJ78 with the 1KZTE. I don’t push it hard, no towing, keep it at about 100kph on the highway, do a bit of four wheeling. Wanting to do a few simple mods to keep it running well and cool enough. It all looks stock, no evidence of head issues. I am thinking:

• EGT gauge (probe pre turbo?)
• Manual boost controller and increase to 14psi
• EGR delete via blocking plate
• Clean the intake
• Higher flow thermostat and replace coolant with Toyota red, it has green in it now

I am just going to chip away at each of these as time permits. So any thoughts on priorities here, or advice regarding install, anything I'm missing?

Would it be OK to increase the boost before the other jobs (as I already have the parts)?

Will get my mechanic to do the coolant change and thermostat.

Will do the intake clean and EGR block together. I see a lot of people remove the throttle body butterflies too, is this necessary, or a separate job to the EGT entirely?

Cheers! Thanks in advance!

 

[Waikato Willy]

i wish I left my butterflies in, I lost them when I cleaned up , certainly a lot safer with butterflies in when mucking around with the spill valve , far easier than a piece of wood in front of the turbo

 

[toddm]

I had my butterflies out for a while but I put it all back in after my cousin had a runaway in his TDI without the shut off valve. For me its piece of mind because you never know when a turbo seal could let go.

If you are just looking to keep it cool, invest in an intercooler if you don't already have one.

More boost will get you more air which should lower your EGT's if the ECU doesn't add more fuel. Either way you get either more power or lower EGT's.

If you do decide to crank it up definitely get a good EGT gage, Pre-Turbo and a boost gage. I have run 20-21psi on mine with an intercooler and a 3" exhaust.

 

[Slowcruiser]

Thanks for that. My ultimate plan will be add an intercooler, looks like the 1KZ-TE in the KZJ78 is the same engine as the intercooled Prado J90s released in Australia, so hopefully won't be too complicated, as long as I can make space, lots of write ups on here for it it seems. But I think the first thing I will do is install the EGT and boost gauges, I have the Aubers, see how hot it runs, then add the boost controller, seems most people on here feel that 14psi is the highest it should be without doing other major upgrades? I guess my question is can I turn it up to 14psi with the stock exhaust, no dump pipe, and without having deleted the EGR or having cleaned the manifold? Dont know even if the intake has ever been cleaned or not, the inside of the throttle body looks actually much cleaner than pics I have seen online.

 

[Waikato Willy]

good plans, my 5 cents though is make exhaust and intercooler priority, the difference these make to any stock non intercooled diesel is night and day, especially how restrictive the factory dump pipe is on a KZJ78

 

[toddm]

I agree with Willy. Also don't worry too much about the boost. Run as much as you need to keep it from smoking. The 14psi limit is probably because of the fuel cut on the ECU. I think its at 15psi, but I would need to look it up. The maximum you can run on your engine is highly dependent on your mods and your environment. The same boost level in the mountains at altitude would work the turbo harder than at sea level. At some point you will over speed the turbo and it will come apart, or you will blow out the head gasket. So far at 20-21 psi and about 600ft elevation mine has survived. I try to keep the EGTs below 1000F sustained, but in the summer with a strong headwind, that can be tough. I have read anecdotal stories about the stock non-inter cooled 1kz reaching 1100F. I never ran mine without the Inter cooler and a full 3" exhaust.

 

[PDXadvokat]

Great questions, right in line with what I'm looking to do too. Following as a fellow Portland KZJ78 owner!

 

[Slowcruiser]

Ahh yes, mods and environment. Well currently it's stock, stock exhaust, though it looks like there may have been a manual boost controller in at some point. Don't know if there are blanking plates on the EGR, seems this is pretty common though. Has 32' tires, manual hubs. It's also the manual transmission. Environment, well currently in Portland, not far off sea level, however we are moving to Albuquerque in a month, so will be up at 5000ft! Wondering if ill have to turn the spill control back a little with the boost up to 14psi? Going to give it a service today (oil + filter, air filter, fuel filter, grease the drive shafts) so will take some photos and get them up on here.

 

[Slowcruiser]

Great questions, right in line with what I'm looking to do too. Following as a fellow Portland KZJ78 owner!

Perhaps we should get together and talk KZs before I move to Albuquerque!