PZ vs HZ

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woytovich

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How much of a difference will it make in the real world between a PZ and an HZ?
If one were to have the opportunity to buy a nice truck that had a pz instead of waiting for the future possibility of finding a nice truck with an hz are there compelling reasons to wait?
 
Well, one is exactly 5/6 of the other. I've heard they both feel pretty slow though. Personally I'd put truck total condition and availability first. You'll probably want to put a turbo on either motor at some point. This will cost you enough, that you could just sell the motor and put the proceeds and turbo funds towards a 1HDT instead. It's a superior motor in terms of efficiency and resistance to overheating in turbo form. Direct Injection is much better.

I suppose one advantage of the HZ trucks is they come with the H55 instead of the R151. Apparently the H55 stands up better to turbo power.
 
I currently own both PZJ and HZJ.

My two cents is that the PZJ defiantly gets better fuel economy but is just missing a cylinder. The R151F shifts much smoother to me than the H55F.

I like them both for what they are.
 
No contest - 1HZ
You can always swap a proper Turbo variant down the road easily (relative)
Biggest compelling reason is the motor is still in production and parts are easily sourced (relative)
Also, no issues overheating with HZ unless Turbo'd
Disclaimer - I do not own a PZ, but love driving the HZ - just not as much as the HDT - but more than a 3B haha. The HZ is similar to a 3FE with more grunt down low and way better economy. Running 265 on a lightweight build, the HZ can keep up and pass traffic even on hills.
It's also the most bombproof motor ever built (if that's not compelling)
 
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PZ all the way! Nice smooth purr of an engine, although a little sluggish on the uphill... bias is in the eye of the beholder (owner) of course. Can comfortably get around 750 to 800km off a tank. That's when running stock everything with 31" tyres.

Sourcing parts can be a little tedious though. Infact, to take a tangental hijack of the thread, I'm in the process of trying to figure out if 1HZ injectors will straight swap in for 1PZ injectors. Does anyone know?
 
PZ all the way! Nice smooth purr of an engine, although a little sluggish on the uphill... bias is in the eye of the beholder (owner) of course. Can comfortably get around 750 to 800km off a tank. That's when running stock everything with 31" tyres.

Sourcing parts can be a little tedious though. Infact, to take a tangental hijack of the thread, I'm in the process of trying to figure out if 1HZ injectors will straight swap in for 1PZ injectors. Does anyone know?


Can’t tell ya on 1Hz to 1PZ injectors but 1PZ are still available as an assembly.

Cheers
 
I found that there are some internal differences within the 1PZ and the 1HZ injector assy when I looked into this awhile back. I don't think I would try using the 1HZ injector assy on the 1PZ engine.

Rebuilding the originals would seem the best way to go.
 
I found that there are some internal differences within the 1PZ and the 1HZ injector assy when I looked into this awhile back. I don't think I would try using the 1HZ injector assy on the 1PZ engine.

Rebuilding the originals would seem the best way to go.

Interestingly, I have just heard back from Toyota (New Zealand) and they reckon the 1HZ and 1PZ injectors are the same for years 1990 to 1993.

Anywho... that's enough thread hijacking for me. I now return it to the rightful owner. Did I mention 1PZs are a good solid engine? Haha.
 
The thing about the 1PZ is it’s a 5cyl so by design, how a 5cyl fires makes it a smooth running engine.

I think that is why Toyota came up with it and used it. Along with things like the duel mass flywheel and r151 it was-is less rugged or heavy duty than a 1HZ H55 70 but still more rugged than a Prado. I think that was Toyota’s aim with it, kinda the mid grade for comfort. Short run on it though production wise so for whatever reason they didn’t keep it in the models offered. 1PZ is the only 5cyl diesel I know of that Toyota made and most certainly the only one put in a Cruiser.

Cheers
 
The thing about the 1PZ is it’s a 5cyl so by design, how a 5cyl fires makes it a smooth running engine.

I think that is why Toyota came up with it and used it. Along with things like the duel mass flywheel and r151 it was-is less rugged or heavy duty than a 1HZ H55 70 but still more rugged than a Prado. I think that was Toyota’s aim with it, kinda the mid grade for comfort. Short run on it though production wise so for whatever reason they didn’t keep it in the models offered. 1PZ is the only 5cyl diesel I know of that Toyota made and most certainly the only one put in a Cruiser.

Cheers

An in-line 5 is smoother than an in-line 4 but an in-line 6 is naturally balanced and will be smoother than an in-line 5.
 
The PZ is a unique engine due to the production run and numbers produced. Having many hours of seat time with both, it all comes down to the condition of the vehicle. If you can get an amazing condition PZ as opposed to just an OK HZ go with the PZ. Both engines can benefit from a turbo, but are still a pleasure to drive without if you are not a speed Demond. Remember these are a Land Cruisers not Land Speedsters. These are a mechanical Diesel engine that provide a symphony to the ears and smile to the driver. Either one can be greatly enjoyed just don't try to compare them to the newer electronic diesels.
 
You should only buy a 1HZ unless they were giving 1PZ's away for next to nothing. There is nothing wrong with a 1PZ as an engine but parts availability and only having 5/6ths the power of a 1HZ make it a no brainer.
 
You will find as I did that PZJ77s are much easier to source. I paid ¥650,000 (right at $6300 at the time IIRC) for mine at auction in Japan. Mine is factory locked as well as factory air conditioning. I doubt you could buy an HZJ77 in the same condition with lockers for twice the money.

The upside is I paid next to nothing for it and it gets better mileage, the down side is it has less power.

People complain about the R151 trans but anyone can tell you it is a smoother shifting transmission and I have run various R series transmissions in different Toyotas for years without a problem. Has there been a rash of them breaking? Not that I know of. I think they are a great transmission.

As far as the power question it gets me where I need to go. Acceleration is slow. We are talking about 113hp and 170lbft. But it turns the 33s it has easily and still hits 75mph with ease on the highway. Won't go a whole lot faster but then I don't need it to. Speed limit around here is 70mph on the highway. I have had it on multiple road trips for 5 hour stretches at a time and it performs flawlessly. I am very happy with my purchase.
 
The answer to most issues ...... :)
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The PZ doesn’t like to tow, and doesn’t like altitude (but will do both of required, albeit slowly). Agree with others, it’s great behind a manual trans and better in a SWB. I will be doing a FT swap on my 77, but would like to keep the PZ for a 40 build.

6BB378EA-999B-4AA1-98F9-07EFC0D9C33C.jpeg
 
Interestingly, I have just heard back from Toyota (New Zealand) and they reckon the 1HZ and 1PZ injectors are the same for years 1990 to 1993.

I would have thought so but those pesky part numbers dont match up. But maybe a fuel injection shop knows how to do it.
 
I would have thought so but those pesky part numbers dont match up. But maybe a fuel injection shop knows how to do it.

So I've delved into the depths of this injector conundrum. Going to start another thread I think and get some conversation going. I think we have higlighted one of the few issues with 1PZ engines... parts!
 

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