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Low Power 4JB1T 490K KM

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Implosion
Posts: 8
Joined: Wed Oct 06, 2021 7:34 am

Low Power 4JB1T 490K KM

Post by Implosion »

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?
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geeves
Posts: 1980
Joined: Mon May 11, 2009 1:56 am

Re: Low Power 4JB1T 490K KM

Post by geeves »

Pump or injectors need attention compression low cam wear etc
Implosion
Posts: 8
Joined: Wed Oct 06, 2021 7:34 am

Re: Low Power 4JB1T 490K KM

Post by Implosion »

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?
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geeves
Posts: 1980
Joined: Mon May 11, 2009 1:56 am

Re: Low Power 4JB1T 490K KM

Post by geeves »

What boost are you getting
Implosion
Posts: 8
Joined: Wed Oct 06, 2021 7:34 am

Re: Low Power 4JB1T 490K KM

Post by Implosion »

Never measured it though it's stock standard and can only feel the boost over 3000 rpm which I rarely do.
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geeves
Posts: 1980
Joined: Mon May 11, 2009 1:56 am

Re: Low Power 4JB1T 490K KM

Post by geeves »

That doesnt sound right. Invest in a cheap boost gauge kit. $25 will answer a lot of questions
Implosion
Posts: 8
Joined: Wed Oct 06, 2021 7:34 am

Re: Low Power 4JB1T 490K KM

Post by Implosion »

Ok off out to buy a boost gauge online
Implosion
Posts: 8
Joined: Wed Oct 06, 2021 7:34 am

Re: Low Power 4JB1T 490K KM

Post by Implosion »

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.
jellis
Posts: 69
Joined: Mon May 11, 2009 7:32 pm

Re: Low Power 4JB1T 490K KM

Post by jellis »

Be careful just winding the fuel up mate, super easy to cook the motor.
Probably should invest in an exhaust gas temperature (EGT) gauge.
Implosion
Posts: 8
Joined: Wed Oct 06, 2021 7:34 am

Re: Low Power 4JB1T 490K KM

Post by Implosion »

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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