Convert HAC to boost compensator

Joined
Jan 31, 2017
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2
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dardanup wa 6236
Hey peeps hows it gling i have a 1998hzj105r gxl that i ground up rebuilt the motor 15,000km ago.
Only thing i didnt touch was the injector pump.

Anyway i just scored a hzj79 injector pump with 260,000 on it for $150. I was going to get it run up to see if its any good but that would just be a bonus as i mainly bought it for the top section

If i was to take the hac off that pump and bolt it ontop of mine what other little mods do i need to do to convert it to a boost compensator.

I remember reading somewhere that someone robbed bits out of a 4jb1t injector pump to complete the mod and i just happen to have one of them laying around from my old ute


I built my motor myself so im keen to have a crack at the pump
 
Joined
Dec 17, 2007
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5,243
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Across the pond, and upside down
Hey mate
The HAC works slightly differently to boost compensator.
The housing is the same, but internally is different.
To use it as boost compensator you need a few parts. And you need to take the top off the pump and disconnect the governor springs to be able to swap it all over.
Not something I'd recommend for a novice unless you've done a lot of research and know what to expect

You can get the parts you need from a few different pumps.
There's a load of cars that use the same type of VE Rotary injection pump.
There's Denso pumps (Toyota, Isuzu version)
Bosch (the original, and used on Cummins, VW and others)
Zexel. Used by Mitsubishi and others

Most parts will be interchangeable, but there will be differences.

There's pics of a zexel pump boost compensator and hzj105 HAC in my turbo build thread linked in my signature
I can't remember what vehicle it came from.
There's a load of different boost compensator pins. Finding one that suits is a challenge
 
Joined
Jan 31, 2017
Messages
2
Location
dardanup wa 6236
Hey mate
The HAC works slightly differently to boost compensator.
The housing is the same, but internally is different.
To use it as boost compensator you need a few parts. And you need to take the top off the pump and disconnect the governor springs to be able to swap it all over.
Not something I'd recommend for a novice unless you've done a lot of research and know what to expect

You can get the parts you need from a few different pumps.
There's a load of cars that use the same type of VE Rotary injection pump.
There's Denso pumps (Toyota, Isuzu version)
Bosch (the original, and used on Cummins, VW and others)
Zexel. Used by Mitsubishi and others

Most parts will be interchangeable, but there will be differences.

There's pics of a zexel pump boost compensator and hzj105 HAC in my turbo build thread linked in my signature
I can't remember what vehicle it came from.
There's a load of different boost compensator pins. Finding one that suits is a challenge
I am a hd diesel mechanic by trade so i have a reasonable understanding how things work, im keen to give it a crack :)
 

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