T27 1.8i 2ZR-FAE Power loss at low rpm

[driftaaja5]

Hello! Update to problem situation: Cleaned throttle body fully and changed spark plugs, initialized system by taking some fuses out. Car runs and idles more better but the hesitation problem at 3000 - 4000 rpm still exists. I looked Lambda value with OBD reader and looks fine whenever I press pedal. Had a chat with friend about O2 & A/F sensors and checked sensors resistance (unplugged wiring harness), from both sensor's heater I do not get any reading (electricity does not go trough). Does sensor heaters need to be on all the time, can this affect to this?  Any other suggestions what to check? thanks

- Drift

[driftaaja5]

3.2023 update to the issue. Changes cheap (biltema) air filter to Bosch air filter, situation did get better. still some hesitation but not that much. Need to test further with trailer + heavy load

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Drift

[driftaaja5]

8.2023 Update to the issue. Issue still existing.. anoying.. Engine / Car soon run 310 000km... Cylinder pressures higher than expected (good)... Carbon capture at cylinder head  / piston. Changing any sensors did not help anything.. have a feeling about issue being in fuel injection (injectors or in tank purge system) or in air supply (pedal or throttle systme working). Once when had throttle body in hand, body had something inside loose, probably gear. can this be issue? Why we cant have easy systems as before, I dont have time.. other stuff to do. thanks that car still running and everything but not allways working correctly
Help is appreciated

-Drift 

[TonyHSD]

Vvti like on Auris 1.6 ? 

[driftaaja5]

Normal VVTI Engine (1.8) VVTI Motor changed once

-Drift

[UlleB]

I have that same issue of 'jerkyness' in the first gear. It's kind of weird. But I've cleaned the MAF and changed spark plugs to Denso SC16HR11 and it didn't really make a difference. None of the suggestions in this thread seem to have solved it for me so I wonder if there's something else going on. I think in my case it may be caused by an overly sensitive clutch whereby if you hesitate a little on the clutch before settling into first it's gonna create this 'jerkyness'. The engine is running fine and is very happy otherwise (14 year old car getting around 14,5-15 km/l fully loaded on the highway and some city driving).

[TonyHSD]

20 hours ago, driftaaja5 said:

Normal VVTI Engine (1.8) VVTI Motor changed once

-Drift

What about the exhaust back pressure? If the cat is blocked ay cause erratic engines behaviour and lost of power. 

[JiiN]

Update to this issue. I bought (without anykind of a advertising) STP complete fuel system cleaner couple months ago and added it to full fuel tank and drove tank nearly empty. Next filling I added STP petrol injector cleaner to tank and been driving many tanks after that.

Engine behaviour is much better now! No hesitation anymore (not sure does it come back when summer comes).

Car feels more powerful and low rpm torque increased noticeably.

Not sure does this help anyone but it was pretty cheap to test.

Oh, and car mileage about 150k kilometers

[UlleB]

16 hours ago, JiiN said:

Oh, and car mileage about 150k kilometers

Just barely broken in. Mine is at 158k 😄

[driftaaja5]

22 hours ago, JiiN said:

Update to this issue. I bought (without anykind of a advertising) STP complete fuel system cleaner couple months ago and added it to full fuel tank and drove tank nearly empty. Next filling I added STP petrol injector cleaner to tank and been driving many tanks after that.

Engine behaviour is much better now! No hesitation anymore (not sure does it come back when summer comes).

Car feels more powerful and low rpm torque increased noticeably.

Not sure does this help anyone but it was pretty cheap to test.

Oh, and car mileage about 150k kilometers

thanks for info. Bought same stuff, lets see how it will work with 315k km ODO T27 Avensis

[JiiN]

2 hours ago, driftaaja5 said:

thanks for info. Bought same stuff, lets see how it will work with 315k km ODO T27 Avensis

I found two kind of a injector cleaners from STP. One was for low mileage cars and another was for higher mileage cars. I bought that higher mileage stuff.