Avensis T25 2006 facelift 2.0 vvti 1AZ-FSE wagon slow acceleration

[morpheusro]

Hi Guys,

Since I've got this car, I've noticed that it's slow to accelerate. Both at idle and under load.

What I did so far: I've changed the oil 3 times, I've changed one O2 sensor that was malfunctioning, I've changed the spark plugs with the correct ones (Denso), I've used 98 octane fuel, I've changed the air filter. I've also installed a set of OZ lightweight wheels and a strut bar :P. (the handling is WAY better now than stock, the strut bar definitely improved the car)

All of the above brought minor improvements, I mean, I can feel slight differences then when I've bought the car, but I'm not pleased. Still feels slow to accelerate and I still have a minor glitch between 2000 rpm and 3000 rpm when the engine is warming up (not when cold, not when hot).

So... any advice? Could be the fuel pump on its way to the grave?

Thanks!

[morpheusro]

What's the nominal fuel pump pressure?

I've checked with my tester and it reports at idle 7 mpa (I assume megapascals) and is increasing under load to 13-14 mpa

[Konrad C]

The first thing I thought of, is the high pressure side of the fuel system may not be delivering a high enough. 

I am not sure of the figures, but just checked a couple of sources.

https://toyota-club.net/files/faq/04-11-20_faq_az_eng.htm

Second source is from the Haynes manual for the Mk1 using the same engine. From the fuel tank 3.7 - 4.2 bar. High pressure side delivery 95.2 -104.8 bar. Remember this is for the T22 using the same engine. The link states 8 - 13 MPa. You need to convert the figures. 1 megapascal = 10 bar. This means you are getting 7MPa (70 Bar), according to a unit convertor. That sound low.
Going by what you have, the pressure is down.
Also check other items mention in the link included above.  

Edited April 15, 2022 by Konrad C
Additional info

[morpheusro]

Thanks for the info!

It's clear, the fuel pump is tired, I need to change it.

Any recommendations what to buy?