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Low Power 4JB1T 490K KM

Posted: Wed Oct 06, 2021 7:34 am
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?

Re: Low Power 4JB1T 490K KM

Posted: Thu Oct 07, 2021 1:11 am
by geeves
Pump or injectors need attention compression low cam wear etc

Re: Low Power 4JB1T 490K KM

Posted: Fri Oct 08, 2021 12:30 am
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?

Re: Low Power 4JB1T 490K KM

Posted: Fri Oct 08, 2021 3:17 am
by geeves
What boost are you getting

Re: Low Power 4JB1T 490K KM

Posted: Fri Oct 08, 2021 6:30 am
by Implosion
Never measured it though it's stock standard and can only feel the boost over 3000 rpm which I rarely do.

Re: Low Power 4JB1T 490K KM

Posted: Fri Oct 08, 2021 6:56 pm
by geeves
That doesnt sound right. Invest in a cheap boost gauge kit. $25 will answer a lot of questions

Re: Low Power 4JB1T 490K KM

Posted: Sat Oct 09, 2021 12:24 am
by Implosion
Ok off out to buy a boost gauge online

Re: Low Power 4JB1T 490K KM

Posted: Wed Oct 13, 2021 7:38 am
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.

Re: Low Power 4JB1T 490K KM

Posted: Thu Oct 14, 2021 10:17 am
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.

Re: Low Power 4JB1T 490K KM

Posted: Tue Oct 19, 2021 6:52 am
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.