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Low Power 4JB1T 490K KM

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Low Power 4JB1T 490K KM

Postby Implosion » Tue Oct 05, 2021 6:34 pm

Hi all
On a budget here. I'd like to get some ideas before spending money on the old girl. I usually do all my own maintenance.

Even with the fuel pump turned up it seems to be slowly losing power over the last few years. When it was brand new it was much more powerful than now. I've owned her since new.

Everything runs just fine though it blows some smoke on start up and blows a big big cloud of smoke under throttle if I don't have the oxy-hydrogen gas turned on.

I don't want to go replacing things just for the sake of it. Though It just seems to be gutless now and I don't want it to stop when I am on a long trip well away from home.

Any thoughts or comments?
Implosion
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Re: Low Power 4JB1T 490K KM

Postby geeves » Wed Oct 06, 2021 12:11 pm

Pump or injectors need attention compression low cam wear etc
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: Low Power 4JB1T 490K KM

Postby Implosion » Thu Oct 07, 2021 11:30 am

Hi Thank You Alan

Can the fuel pump be checked using a pressure gauge on the return line?

Do the injectors get clogged on an old mechanical pump style system?
Implosion
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Re: Low Power 4JB1T 490K KM

Postby geeves » Thu Oct 07, 2021 2:17 pm

What boost are you getting
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: Low Power 4JB1T 490K KM

Postby Implosion » Thu Oct 07, 2021 5:30 pm

Never measured it though it's stock standard and can only feel the boost over 3000 rpm which I rarely do.
Implosion
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Re: Low Power 4JB1T 490K KM

Postby geeves » Fri Oct 08, 2021 5:56 am

That doesnt sound right. Invest in a cheap boost gauge kit. $25 will answer a lot of questions
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: Low Power 4JB1T 490K KM

Postby Implosion » Fri Oct 08, 2021 11:24 am

Ok off out to buy a boost gauge online
Implosion
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Re: Low Power 4JB1T 490K KM

Postby Implosion » Tue Oct 12, 2021 6:38 pm

Dialed the fuel right up, idling at 1000 rpm as the fuel pump hasnt got enough range when dialed right up. Goes like a petrol sedan now.
Waiting for the turbo boost gauge.
Implosion
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Re: Low Power 4JB1T 490K KM

Postby jellis » Wed Oct 13, 2021 9:17 pm

Be careful just winding the fuel up mate, super easy to cook the motor.
Probably should invest in an exhaust gas temperature (EGT) gauge.
cheers, Josh
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Re: Low Power 4JB1T 490K KM

Postby Implosion » Mon Oct 18, 2021 5:52 pm

Whoo OK. I drove up Mt Ousley the other day with a trailer on and the water temp shot right up. Round town seems OK temp gauge stays rock solid.
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Re: Low Power 4JB1T 490K KM

Postby Implosion » Mon Oct 18, 2021 5:53 pm

Oh I also put the hydrogen on seems to burn off all the diesel fuel I'm pumping into it
Implosion
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Re: Low Power 4JB1T 490K KM

Postby geeves » Tue Oct 19, 2021 3:34 pm

Most common cause of overheating under load seems to be failing viscous fan clutches. Test yours
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: Low Power 4JB1T 490K KM

Postby Implosion » Tue Oct 19, 2021 5:50 pm

Yes my fan is dead. Also the fan cowling is missing a bit of plastic.
Implosion
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Posts: 8
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Re: Low Power 4JB1T 490K KM

Postby geeves » Wed Oct 20, 2021 9:54 am

that can do it
Sanding your knuckles before starting work can help. That way you cant skin them
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