Fj73 fuel economy

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Joined
May 17, 2020
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Location
melbourne, australia
Hey guys I’ve got a fj73 with 3f and a440 running on petrol and gas and fuel economy is just killing me it’s roughly running 30L/100 on gas and 20L/100 on petrol
Has anyone been able to reduce this at all and what are my options to fix this engine or to try and swap the engine possibly just completely swap over to diesel, only issue is I’m currently on my P plates in Victoria and so I’m very limited but putting in a engine that’s been in any MWB I’m sure the cops would be none the wiser
 
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Best thing is a 1HZ, it needs some new engine brackets welded on . Do it properly and the cops will pass it first time.
They just checked the welding, exhaust, electrical and charged a half inspection fee. This was in Perth.
Much of the things that bolt to the engine had to swapped from one side to the other.
And you'll need another radiator

But it maybe out of your budget. I spent about $10k but I had a rebuilt engine and most of the things that bolted to the engine were new or refurbished.
I think you could save a lot if you could find a totalled HZJ75 ute or troopy but its going to cost the best part of $5k I think doing it cheap.

You'll also need to put the 1HZ input shaft into your auto which means a strip down.
A440 autos for 1HZ are not common in Australia, they are available from Japan but thats a whole new rabbit hole.
 
Best thing is a 1HZ, it needs some new engine brackets welded on . Do it properly and the cops will pass it first time.
They just checked the welding, exhaust, electrical and charged a half inspection fee. This was in Perth.
Much of the things that bolt to the engine had to swapped from one side to the other.
And you'll need another radiator

But it maybe out of your budget. I spent about $10k but I had a rebuilt engine and most of the things that bolted to the engine were new or refurbished.
I think you could save a lot if you could find a totalled HZJ75 ute or troopy but its going to cost the best part of $5k I think doing it cheap.

You'll also need to put the 1HZ input shaft into your auto which means a strip down.
A440 autos for 1HZ are not common in Australia, they are available from Japan but thats a whole new rabbit hole.
Ideally I’d put in a 1hz but just have to make sure that VicRoads will allow it because they’re the ones that’ll decide in the end (legally) having the donor car would be perfect too and the strip down would be worth it in the end
 
I just read that there was a hzj73 model in Japan that is just a fj73 with a 1hz, would that then classify the 1hz as a possible “stock” motor in the car because one of vicroads rules is that the motor replaced has to have been a stock option to a degree
 
I just read that there was a hzj73 model in Japan that is just a fj73 with a 1hz, would that then classify the 1hz as a possible “stock” motor in the car because one of vicroads rules is that the motor replaced has to have been a stock option to a degree
Yeah theoretically I think that would fly. Another option is a 12HT which would be not far off bolt in where a 3F came out, but they ain't easy to come by these days
 
I just read that there was a hzj73 model in Japan that is just a fj73 with a 1hz


They sold a few here as well and the PZJ7*, but rare. The heavy duty 7* had about 9 engines . I cant see it being a problem as the states go by the Australian Standards rather than state rules these days.
 
Best thing is a 1HZ, it needs some new engine brackets welded on . Do it properly and the cops will pass it first time.
They just checked the welding, exhaust, electrical and charged a half inspection fee. This was in Perth.
Much of the things that bolt to the engine had to swapped from one side to the other.
And you'll need another radiator

But it maybe out of your budget. I spent about $10k but I had a rebuilt engine and most of the things that bolted to the engine were new or refurbished.
I think you could save a lot if you could find a totalled HZJ75 ute or troopy but its going to cost the best part of $5k I think doing it cheap.

You'll also need to put the 1HZ input shaft into your auto which means a strip down.
A440 autos for 1HZ are not common in Australia, they are available from Japan but thats a whole new rabbit hole.
hey mate, thinking of buying a 3f one and was wondering for in the future how easy it is to do the 1hz swa, was there much needed apart from engine mounts? would be a manual too, and am yet to look at it but id rather not have the 30 litres per 100 like some people have said. im located in perth too if any help or photos could help? the one im looking at seems to have a mint body and the fuel economy isnt on the worse side of 3f economy yet. just hoping a 1hz swap isnt crazy hard, and i have some mates who are quite experianced with 1hz 75s
 
I have 3F and A440f in my FJ73, and the fuel consumption is no where near 30lt/100km.
More like 15lt per 100 when pushing hard (2.5 hours up the mountains to the good fly fishing spots hehe)
Can easily get 12lt/100 driving nicely.
Gotta remember these are literally a truck engine and have the power band lower in the rev range. 80 to 90kmh seems like a nice 'max cruise' speed without leaning too hard on it.
I only have 31" tyres too. Anything bigger than that will easily upset economy.
It took me a good 3 months of driving to get the feel of it, but there is a sweet spot in the rev range that it seems to really fly along, almost like when you can only use the accelerator to keep the momentum.

Comparing the 1HZ and 3F, they are actually very similar. The 3F has basically same power but for a much broader rev range.

I wouldnt touch a 1HZ unless it had a rebuild and that includes the pump. Adding a turbo normally ends in much butthurt unless you keep the boost low.
Finding a 1HDT from an 80 series may be more beneficial, (more power, decent reliability, decent economy)

Also dont overlook the 1FZ. It was a factory option and even with 15lt/100km the power is very nice in a 75.
I had a brain fart and was looking at importing a 1FZ carb intake manifold and playing silly buggers with a holley EFI and turbo.
Upgrading petrol engine is always going to be easier and cheaper that diesel conversion. (unless you have access to a wreck or damaged auction vehicle)
 
Hey guys I’ve got a fj73 with 3f and a440 running on petrol and gas and fuel economy is just killing me it’s roughly running 30L/100 on gas and 20L/100 on petrol
Has anyone been able to reduce this at all and what are my options to fix this engine or to try and swap the engine possibly just completely swap over to diesel, only issue is I’m currently on my P plates in Victoria and so I’m very limited but putting in a engine that’s been in any MWB I’m sure the cops would be none the wiser

Excuse my ignorance, but what is the difference between gas and petrol? I thought it was the same thing just different names? Or by gas do you mean propane or natural gas?

Carb rebuild might help you? Drive it nice as described above too....
 
In Aus, gas usually refers to LPG (liquid petroleum gas) which really is just Propane.
There was a govt subsidy for vehicle owners to get a conversion kit fitted so we all could use LPG as a cheaper fuel.
By the time everyone was running LPG tanks (as a secondary) the price went through the roof and the savings didnt make all that much difference. Especially since it was alot less efficient (20% worse or something)
plus it stunk like a bbq and burned up alot of engines from high heat exposure....
 

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