2005 Vvti 2.0 Struggles

[scottambrose]

hi hope someone can shed some light for me.

My 2005 avensis vvti 2.0 t4 has an issue. i had the eml on which indicated 02 sensor bank 2 sensor 2, ive changed that and reset the codes and driven about 800 miles now and the light has stayed off.

But the problem ive had ever since i got the car in june is still there. basically unless i boot it and get above 3500rpm it hesitates and has no power and feels very sluggish. up hills you have to be above 3500 rpm or it dies and you have to change down a gear, and when you pull away at roundabouts in first it takes a few seconds to actually get any power.

ive read the ecu with a snap on solas and no fault codes. its great on fuel does upto 45mpg on the motorway , almost seems too good on fuel.

any ideas.

thanks

[Aidan-]

When was the last time it got a good service.

[scottambrose]

it had a full service plugs air filter oil etc about 4000 miles ago

[Aidan-]

Your fuel economy is excellant for a 2.0l i thought i was doing good with a 1.8 at 42mpg. But back to the problem at hand how many miles is on the car, and have you tried any engine cleaning additives you put through with your fuel.

[RUToyota]

Fuel filter.?...MAF clean.?...have you tried an ECU reset.?....sounds as though it could be a coil pack but that would usually throw a code.?

I assume it starts and idles OK..?.

Neil

[scottambrose]

is starts fine its on 145k miles got full history. had a recent clutch 3000 miles ago

. ive added some fuel cleaners over the last 3-4 months. cleaned the maf yesterday and throttle body again which was clean anyway. its fine if i put the pedal to the floor but trying to accelerate gently at low revs it splutters. where is the fuel filter located. i could try seeing if thats dirty or blocked. also done an ecu reset.

cheers for all the help

[RUToyota]

OK...I think the fuel filter is located on the bulkhead below the windscreen.

I think I'd check for DTC's again using a different OBD reader....just in case.!...given it's had new plugs, I still wonder if you have the possibility of a failing coil pack/s.?

Checked all your vacuum pipes are secure..or split..?...cleaned the Idle Air Control Valve.?

Neil

[Aidan-]

Does the car idle ok (as in steady) and now that you have done the basic stuff with no joy :( , it's time too start eliminating the things Neil has recommended.

[Mr.D]

Hi,

If i may, i would suggest to check weather this new O2 sensor was really ok, for some reasons they happen to be faulty ( as all production even produced by machinery has up to 3% production errors), maybe unpluging the new O2 sensor and see how car behaves in driving conditions, same or worse, if worse, then it might be good, but not 100%. Would be best if you could get a data sheet on what happens under the bonnet, mini VCI chinese version does that very well, i could tell more based on it. Let's say O2 is good, then have you tried motorway driving 10-20km with revs no lower than 3500? Might be backpressure is too high, but this should have been adding up over time, not suddenly. Disconnect MAF check same or worse conditions. Then idle and catching speed rapidly, is there vibration? If so, then one or more of coils are dead. Also there might be a lot of other things like fuel rail preassure valve, fuel pump temperature sensor, VVTI sensor ( that controls oil flow to activate VVTI, this might be a good shot) and many other things. If you would find somebody with mini-VCI, then it would show all O2 sensor voltage output, pressure rail pressure, injection timing and injectors compensation ratio's, temperature of fuel, MAF sensors air flow calculations etc., this would give a lot background to check just in numbers. Oh and also, check your exhaust piping ( especially flexible part between exhaust manifold and catalytic converter), if this has hole or is loose it lets the air in-out, then O2 sensors are having wrong readouts and then fuel-air ratio is wrong.

[RUToyota]

yep...I assumed the OP replaced the O2 sensor with a "proper" one and not some cheaper "eBay" type .???...notorious for a short life and/or inefficiency.

It is a process of elimination I'm afraid.

Neil

[scottambrose]

fitted a decent o2 sensor and it ran better as soon as i replaced it. no split pipes. it seems to idle ok. tried another scanner today and no codes read on that either. exhaust is all sealed ok, only other thing ive noticed is exhaust steam? sometimes seems more than i would expect at this time of the year. uses no water or oil and more are clean and not gunky etc. il try unplugging maf and run without that see if there is a difference. its almost like it runs too lean( maybe why such good mpg) and then when i need a bit more fuel under load its not there.