are 1HZ the same as the 1HDT but without turbo

[vorno_18]

im looking to upgrade to a 80 and want a turbo diesel but wondering are the non turbo diesels the same engine without the turbo, would i be better off getting a non turbo and buying a turbo kit? im thinking this because finding a non turbo is easier and an after market kit im assuming is better then the standard ones

can anybody help me out

thanks

[dow50r]

block is almost thesame, everything else is different, buy a hdt...much more power than 1hz t

[bad_religion_au]

isn't the 1hdfte or whatever it is even better?

[just cruizin']

The multivalve turbo engines are totally different, more water and oil galleries. There are the pick, I think they also have electronic injection. I may be wrong, but this allows for chip to be fitted upping the power further.

[smithie]

The only factory turbo engines offered in the 80 series were the 1HD-T 12valve (1990-1995) and the 1HD-FT 24 valve, also known as the multivalve (1995 +)
The 1HD-FTE was the 24 valve electronic factory turbo offered from about 2000 onwards in the 100 and 78/9 series

The 1HZ is an indirect injection diesel, whereas all of the factory turbo engines were direct injection

The 1HZ can make decent power with an aftermarket kit, however it can only handle low boost levels due to the small precombustion chamber orifice.
If its just for general use a 1HZ turbo would be fine, if you tow anything or want to raise boost levels, I'd go for a factory turbo, with the 1HD-FT being the pick of the bunch.
As a precautionary measure I'd replace the Big End Bearings in any of these engines (including a 1HZ with aftermarket turbo) with ACL ones.

[Suspension Stuff]

The 1HZ is an indirect injection diesel, whereas all of the factory turbo engines were direct injection

I have a 90 model 1HDT and it is indirect injection or so I have been told. How do I check this?
EDIT Above is garbage one particular Toyota mechanic in Mt Isa wouldn't have a clue. He obviously doesn't get on Outers.

[Toli]

The 1HZ is an indirect injection diesel, whereas all of the factory turbo engines were direct injection

I have a 90 model 1HDT and it is indirect injection or so I have been told. How do I check this?

I was under the assumption that all the 4.2 1HDT (that is factory turbo) are direct injected. guy at work here has a 90 model as well and it is direct injected.

[smithie]

I have a 90 model 1HDT and it is indirect injection or so I have been told. How do I check this?

If your engine is a 1990 model 1HDT it will be direct injected.
All 1Hx FACTORY turbo engines are direct injected. The only way that your engine would be indirect injection is if it is a 1HZ with an aftermarket turbo.
Check your vin number it will either start with 1HZxxxx or 1HDJxxxx.

[Suspension Stuff]

I went into Toyota and they told me that the 1st of the 1HD-T engines were indirect injected. Mine is 5th month 1990 and from several different sources mine is indirect. It is definitely not a HZ but factory Turbo 1HD-t Automatic Sahara.

Because I do have doubts when I get a chance I will check this out with another Toyota dealer.

EDIT: I have now spoken to an engine builder and they have said that they are all direct injected and I beleive him because he reconditioned my engine. Boy it is hard to get good help.

Shane

[Chucky]

The 1HZ is a solid proven engine that takes turbo's well.
I have a 94 DX cruiser running a aftermarket DTS turbo and intercooler setup which is running 18psi.
I have never had a problem with this setup and the engine has done close to 120,000 km's since the turbo was added returning around the 12.5L/100km city driving and around 15.5L/100km towing the O/R camper with roof rack fully loaded.

[smithie]

As far as I am aware all 1HD-Txx engines were Direct Injected, hence the designation in the engine name.

I'd be interested to know what the Toyota guy was going on about, but from my dealings with Toyota I usually just assume that they are wrong.
Even some of the info you can read on the net is not correct (ie; the Toyota FAQ page often linked to from technical forums has the 1HD-T and 1HD-FT listed as indirect injection )

If you wanted rock solid proof you could have whipped of the head and looked for a pre combustion chamber (Indirect Injection)

Glad you've got it sorted though.

Cheers.
Dan

[smithie]

The 1HZ is a solid proven engine that takes turbo's well.

I'd agree, as proven by the many people running aftermarket turbos with no problems. Any problems usually stem from incorrect tuning for that specific vehicle.

IMO the Direct Injection design is more resiliant to performance upgrades without sacrificing reliability but 1HZ-T's are no slouch and can be just as reliable as factory turbos if set up correctly, it just depends on what you want for your application.


Cheers
Dan

[sniper]

I have the factory books that came with the car. Mine is a 90 model. It is a 1HD-T direct injection
NO 1HD-T came out with indirect injection according to the owners manual. Plus my mechanic has confirmed this and so has my local TMCA.

My pic was the 1HD-T 1st its cheaper then the 1HDT-F 2nd IMO better then the 1HZ.

Been told/recomended to change big end bearings no matter what model 80 you buy. This was also recomended by local TMCA and also my mechanic. The early 1HD-T were recalled, but this dosnt meen the previous owner took it in. Plus should change them every 100k with your timingbelt and tensioner (recomendation again only)

[Suspension Stuff]

Even after getting my pump reconditioned my 1HDT was a slug off the mark so I took it back to them and it improved quite a lot.

Recently I took it to get put on the Dyno and it was way under fueling and putting out under 65kw at the wheels (Bad for the engine, if the temperature guage read accurately it would have shown my engine getting very hot).

After Dyno and tune, it put out over 75kw and the power difference was very very noticeable.

Today I got a 3" exhaust fitted and now it puts out over 82kw and probably more when it gets hot. The boost wasn't altered at 10psi.

So whatever you decide on, a Dyno tune is well worth the effort. I'm hoping for better ecconomy also.

[sniper]

I would actually like to dyno mine. Might help in the runining of the car. I have no probs in power or anything. But for all i know it could be improved more That would make me even happier

[vorno_18]

thanks for all the info guys still deciding which way to go atm

im looking to do not as much "serious" 4wd eg. mud bashing and deep water etc but more longer trips like fraser island and taking it up to the cape, but still wont to be able to do the odd mud holes and such.

which way is better to go, a 1hz turbo or factory turbo, money will be an issue and what is a rough price on each.

i could afford a 1hz first and do the turbo install when i save more, so thats what im thinking

any more info would be great

thanks

[Toli]

thanks for all the info guys still deciding which way to go atm

im looking to do not as much "serious" 4wd eg. mud bashing and deep water etc but more longer trips like fraser island and taking it up to the cape, but still wont to be able to do the odd mud holes and such.

which way is better to go, a 1hz turbo or factory turbo, money will be an issue and what is a rough price on each.

i could afford a 1hz first and do the turbo install when i save more, so thats what im thinking

any more info would be great

thanks

Test drive both and make up ypur mind if you can aford it.

[mud4b]

im in the process of mounting a t3/t4 highmount and external wastegate to my factory 1hd-t.
just so people know the exhaust manifold stud patterns are the same between the 1hd-t and the 1hz although the internals of the head are different.

[hdj105]

Recently I took it to get put on the Dyno and it was way under fueling and putting out under 65kw at the wheels (Bad for the engine, if the temperature guage read accurately it would have shown my engine getting very hot).

Common diesel misconception. Diesel = More fuel = more heat (and less fuel = less heat).

Petrol engine = lack of fuel / lean mixture = hotter combustion

[Joombi]

2 things I have been told,
if you can start it without glowing first thing in the morning and it fires straight away, its direct injected
&
the 1HD-T will slot straight into a yota where a 1HZ was but the 1HD-FE you have to muck around a bit because some of the components are on the other side.
I know the first is true but the second I have never done so I don't know

[hdj105]

the 1HD-T will slot straight into a yota where a 1HZ was but the 1HD-FE you have to muck around a bit because some of the components are on the other side.
I know the first is true but the second I have never done so I don't know

It's a 1HD-FT, and everythings on the same side as all the 1H* family.

[Joombi]

oops!, sorry bout the typo & the totally wrong info

[vSAHARAx]

All Factory Turbo 80's were direct injection, look at the little sticker on both sides near the tail lights, they all originally said (1990-95) "Direct Injection TURBO" Then (95-98) "TURBO Multi-Valve" Then (2000-03) "4200 TURBO Electronic Direct Injection" Then (2003 Onwards) "TURBO". My HJ61 is Direct Injection so Toyota Wouldnt have gone backwards in technology (Well with their motors anyway)

[eye-for-detail]

Yep all 1HDT's were direct injection ( ie. no glow plugs, fuel directly into bore) and 1HZ's were indirect (ie. glow plugs, and fuel into combustion chamber)

[dow50r]

Yep all 1HDT's were direct injection ( ie. no glow plugs, fuel directly into bore) and 1HZ's were indirect (ie. glow plugs, and fuel into combustion chamber)

1hdt's do use glowplugs...most diesels do...direct or non... i found out yesterday that even the viscous fan is different 1hz to 1hdt....and you wouldnt think there would be a difference in that department...

[sniper]

If you pay attention to the dash when you turn the ignition on in a 1HD-T you will see the glow plugs light, light up for half a second if that. They still use glow plugs it just works quicker.

[dow50r]

If you pay attention to the dash when you turn the ignition on in a 1HD-T you will see the glow plugs light, light up for half a second if that. They still use glow plugs it just works quicker.

Yep, my hdft does aswell, but to be fair to Eye for detail...it doesnt have glow plugs like a hdt, but a air heater screen....most dont notice the plugs on a hdt, they are not needed in our climate..