My Toyota Camry Fuel Usage? A Little Crazy

[hecktikbro-mcv36r]

Hi, Im quite new to the forums here.

I've got a 2005 MCV36R Toyota Camry Ateva now my fuel economy is around 17.8L/100km = Pretty crazy i think for a camry, either im a crazy driver or theres something wrong. I've tried fuel injector cleaners a few time ran the engine out all the way with the stuff, didn't really impact it. Any other ideas to what it could be?

Regards

John

[Mole]

Could be the O2 sensor (aka oxygen sensor, aka lambda sensor) has gone bad, that can effect consumption. How are you calculating consumption? Onboard computer or comparing fill ups?

[hecktikbro-mcv36r]

Could be the O2 sensor (aka oxygen sensor, aka lambda sensor) has gone bad, that can effect consumption. How are you calculating consumption? Onboard computer or comparing fill ups?

I've calculated consumption both by the onboard computer and comparing fill ups, because it's been happening for about 6 months now. so you think the o2 sensor ? anyway to check this, will an OBD be able to determine if the sensor is not working properly?

[STYLSH]

Holy *****! Is your accelerator an on/off switch? There is definitely something wrong there and it's been happening for 6 months? Does the car still feels normal when driven, eg powerwise, idling wise?

[Ozzcaddy]

What type of fuel are you using?

[Noodle Boy]

4 cylinder or 6? where abouts are you driving to get this fuel economy?(in the metro area or highway?).

[Andrew357]

4 cylinder or 6? where abouts are you driving to get this fuel economy?(in the metro area or highway?).

It'd be the 6-banger. The MCV36R have the 1mz, the ACV36R are the 2az.

I was getting high 14's before I started modded, but what OP is getting hurts.

[thSydney]

Mate, 17.8L/100km is scary consumption, isn't it. Did you always use A/C ?

[camsport]

Mate, 17.8L/100km is scary consumption, isn't it. Did you always use A/C ?

I'm finding also that the fuel consumption is way too high.

2003 Camry Sportivo 3.0 v6. Best Fuel consumption so far

is 14.8L\100 kms BUT this is driving with no a/c and like a priest!

So far have done the following: Spark plugs, air filter, synthetic oil, double checked tyre

air pressure.

Idle seems way too high on start up but drops off after about 5 mins, acceleration seems to lag

and kickdown (auto) will only activate after a serious thump on the pedal.

Can't find anything in the workshop manual on the servo set-up that links the accelerator

to the throttle. The cables feel slack and there is very little travel in the pedal though

I do get Wide open throttle.

Not convinced that a 3.0 is enough to get the Camry around, my Ford 4.0L battle-wagon does 12.5

L/100 kms eyes shut and gets the car going.

Am I missing something?

[Whip Cracker]

Wow... that's a crazy amount of fuel for a 3L engine...

I must say, mine's not too great either, but not THAT bad. I have the 3VZ engine anyway.

It could possibly be the 02 sensor... pretty sure that's the thing that determines the amount of fuel that is used by the incoming air flow.

Good luck either way.

[camsport]

I'll get into these today.

I think they need an ohm resistance of about 13 at 20 degrees.

When I got the car the upper O2 sensor was disconnected and I didn't give it much thought!

Will post later on findings...thank you!

[Hiro]

Disconnected O2 sensor will make the car run crazy-rich in closed-loop mode (which is what you are in when you are pottering around town, it only goes to open-loop when you floor it), which would explain the heavy fuel consumption.

[trentmeyer23]

Disconnected O2 sensor will make the car run crazy-rich in closed-loop mode (which is what you are in when you are pottering around town, it only goes to open-loop when you floor it), which would explain the heavy fuel consumption.

I could have swore closed loop was when the O2 sensor heated up(ECU controlled AFR) and open loop was when the car first started(determines fuel amount by coolant temp and MAP/MAF). Just remembering back to trade school.

[Hiro]

Disconnected O2 sensor will make the car run crazy-rich in closed-loop mode (which is what you are in when you are pottering around town, it only goes to open-loop when you floor it), which would explain the heavy fuel consumption.

I could have swore closed loop was when the O2 sensor heated up(ECU controlled AFR) and open loop was when the car first started(determines fuel amount by coolant temp and MAP/MAF). Just remembering back to trade school.

It'll probably run open-loop when warming up because the car will still be in rich cold-idle mode. Closed-loop is for normal cruising at temperature (as in the O2 sensor is providing feedback to the ECU), it gets ignored again (ie open-loop) and the ECU runs off pre-programmed maps when you go WOT.

[camsport]

Bugger..O2 sensors are fine, measured 13 ohms accross pins 1 and 4 when cold.

The rear sensor is crazy to get to!

The car runs like a swiss watch once it's warm and the rpm's drop but like

I said I need to figure out how the pulley/servo set-up works and make sure

it is working right.

Still can't find any specs or reference to this unit in the manual.

The quest continues!

[hecktikbro-mcv36r]

Well i've reset the ecu three times, everytime i reset the ECU and try driving normal it gives me great consumption till about half a tank. Then for some weird reason it seems to go back into the 16/17L per 100km. My mate used the OBD and said the o2 sensors seemed fine but I'm not convinced. Maybe worth it to try running fuel injector cleaner again??

I really am stuck with this issue, i drive quite a lot and this is really burning a hole in my pocket, i use Standard unleaded but every so often i fill up with the premium to keep it clean.

[Andrew357]

Well i've reset the ecu three times, everytime i reset the ECU and try driving normal it gives me great consumption till about half a tank. Then for some weird reason it seems to go back into the 16/17L per 100km. My mate used the OBD and said the o2 sensors seemed fine but I'm not convinced. Maybe worth it to try running fuel injector cleaner again??

I really am stuck with this issue, i drive quite a lot and this is really burning a hole in my pocket, i use Standard unleaded but every so often i fill up with the premium to keep it clean.

Unless you're reading with a proper OBD reader, you'll only read that there is a code. I'd probably bring it into a non-toyota workshop to have a look at it.

[Son Gokou]

Wow that some crazy figure for the fuel usage!

Even my 2001 JZX110 2.5 VVTI turbo uses around 11L / 100km.

[Ki Hoon Kim]

I have toyota camry 2002-2006 sportivo V6 and by computer, 22L/100KM. At the fuel up comes to be about 16L/100KM.

I had 2000 Avalon V6 3L, Had about same. Full tank(60L) of premium fuel would last 380-400KM.

Did you figure out what was wrong? Yes, I do have heavy foot..... Maybe my foot needs diet????

[STYLSH]

wow 400km per tank! Holy bejesus! You have an obese right foot! :P

[Evgeni]

^{Testing resistance is not really a good test when a sensor has been installed and used. You are much better off testing voltage when the car is running. O2 sensors send voltage back to the ECU >0.5v equates to a rich mix and <0.5v will mean a lean mix. To provide these figures, the sensor will sample oxgen from the inside of the exhaust and also from the outside, so it is a good idea to make sure that the outside of the sensor is clean.}

^{Also when you test, make sure that the car is up to temperature, so get your probes into the connector prior to starting the car.}

^{It would be handy for fuel trim figures to be read. Also a fuel pressure balance test will let you know if you have a leaking injector etc.}

^{Hope this helps.}

Edited February 22, 2012 by Evgeni

[Martinj]

The quest for fuel efficiency is seldom an easy one, but one that is well worth the pain, I assure you.