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4jb1t high milage adjustments

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4jb1t high milage adjustments

Postby Nzrodeo » Tue Sep 12, 2017 5:05 pm

Hi there I am looking at giving my 4jb1t a little more power. I'm planning on giving it a bit more fuel and boost. I've read the other threads and understand I'll need to run a boost and egt gauge to do so and avoid destroying my engine. My only concern is that my engine is currently sitting on 360000kms. It is in good condition but I am wanting to know if this is too high a milage to do these adjustments?
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Re: 4jb1t high milage adjustments

Postby geeves » Wed Sep 13, 2017 5:50 am

Replace all your water hoses especially the set of 4 that go to the oil cooler. These are probably original and many years past use by date. We hear of an engine failure because of these hoses most years. If it has good oil pressure and not fuming it should be good to go. In trucks these engines clear the million kms. In bighorns we have documented 480k but there are probably higher mileage engines out there.
Otherwise 2.5 inch exhaust. Free flowing air cleaner blok the pipe to the waste gate and you should have around 17 pound boost and the fuel compensator will adjust the fuel. A boost guage will just confirm the result. If you want more then egt guage and tweak the fuel and timing
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: 4jb1t high milage adjustments

Postby Nzrodeo » Thu Sep 14, 2017 6:23 pm

Sweet as. Will upping the boost actually give any power benefits? From what I understand it's increasing the fuel that gives the extra omf. But if I do so won't it be necessary to increase boost to compensate for the air fuel ratio?
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Re: 4jb1t high milage adjustments

Postby isuzurob » Thu Sep 14, 2017 7:32 pm

Increasing the boost won't give you much more power, diesel is more fuel=more power but =more heat, hence using a egt gauge, normally turn fuel screw in until has small black puff of smoke when you free rev it
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Re: 4jb1t high milage adjustments

Postby geeves » Thu Sep 14, 2017 7:42 pm

What is the cut off for the boost compensator? ie it adds fuel to what psi?
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: 4jb1t high milage adjustments

Postby isuzurob » Thu Sep 14, 2017 8:32 pm

Adds fuel for any boost pressure and is adjustable but doesn't put enough fuel in to make a difference, increasing boost will help to lower exhaust temps so will exhaust and intercooler, my 2.8 rodeo went mint standard and fuel wound up and compensator played with until exhaust manifold broke in half=to much heat, has big turbo also now though
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