Landcruiser hzj78 1HZ no power

Hey guys,

i have a few questions i need some help on.

My 1HZ non Turbo troopy feels very underpowered.

On slight hills i have to rev the engine up to 3000rpm to shift from 2nd to third or from third to 4th.

Even then the next gear has barely any power and the rpms drop.

Below 1500 rpm there is almost never any power. Even on flat ground in 1st or 2nd gear there is not much torque below 1000rpm.

I can still drive it normal on flat grounds but the moment i encounter hills i have to drive slow speeds at 2nd or 3rd gear at 2000-3000rpm. Every gear above is impossible to hold any power even above 2000rpm.

Back when i had my 2002 prado 95 petrol it was driving super sluggish on the main tank and quite powerful on the sub tank so i thought tits just a blocked fuel strainer on the 1hz tank.

But it feels sluggish on the main and the sub tank.

Is it normal that the sub tank on a troopy only holds 20 liters??? I filled it up and i could only put 20 liters. The fuel gauge also drops significantly after driving it on the sub tank for a while so i dont understand whats going on. Isnt the sub tank supposed to hold 90 liters??

Long story short i dont know whats going on with the power of my 1hz. I changed both fuel filters but no change.

Does anyone have any ideas?

Cheers