Air flow sensor

[Bear Senior Member Find all posts View Profile Close Bear]

Hi all,
My fuel consumption has jumped from 13.3l/100 to 15l/100 ???. I had the fuel filter changed today and the local Toyota dealer suggested that the Air Flow Sensor (meter?, can't quite recall the terminology) could be the problem and that it might need a clean.
Wonder if anybody could help by shedding some light on this?
Thanks
Bear

[Matt Senior Member Find all posts View Profile Close Matt]

hi bear..

some things i have checked after returning higher fuel consumption - Tires.. Run at least 38-40 psi in the tires to get optimal fuel effeciency.

depending on the KMS it has done, i would suggest running some injector cleaner thru it.

[Bear Senior Member Find all posts View Profile Close Bear]

Thanks Matt, I will check air pressures tomorrow ... can't remember what they are at, and run some injector clean.

Wonder if anyone is able to shed some light on the Air Flow Sensor thingy?

[speedcomm Senior Member Find all posts View Profile Close speedcomm]

The drama rears its ugly head in 90 series 3.4 litres, but havent heard of it in the 120s 4 Litre. He may have been 90/120 challenged maybe ?

[Bear Senior Member Find all posts View Profile Close Bear]

Speedcom wrote:
The drama rears its ugly head in 90 series 3.4 litres, but havent heard of it in the 120s 4 Litre. He may have been 90/120 challenged maybe ?

The toyota guy reckons there is some sort of sensor in the air intake that serves to control the mixture ... any dirt in it and it messes with the mixture. Talking to another mechanic and he said the same sort of thing as yourself; its a different set up in the 120 series. Hmmm, would like to have the facts straight on this.

Also, went for a run with some injector cleaner and have taken on a full load of fuel. Will be interesting to see if there is an improvement.

[Damien Parker Advanced Member Find all posts View Profile Close Damien Parker]

I dont think that the 120 V6 uses as an Airflow sensor as such. They are located before the throttle body on the inlet path after the filter to prevent dirt from fouling. I have not seen this on my V6. If its there it must be under the inlet plenum.

I would say they use MAP sensor instead to control the mixture in conjunction with the EGO in the exhaust.

Ensure that your air filter is clean and your tyre pressures are good. Run some injector clean through at your next fuel stop as well.

I am going through a similar issue myself and i am up to the injector cleaner.

[Bear Senior Member Find all posts View Profile Close Bear]

I've now taken the following action:
a) Replaced fuel filter
b) Gave the injectors a good clean
c) Increased tyre pressure from 33 to 38 psi ... forgot i had the pressure down :?
d) Cancelled the Toyota visit ... will keep the dollars for more fuel :lol:
Not doing much travelling at the moment so is likely to be a couple of weeks till fuel consumption is recalculated.

Damien, I will be interested to hear how you go.

[Bear Senior Member Find all posts View Profile Close Bear]

Bit of an update:
Fuel consumption remains at a steady 15l/100k. Next step, remove the hiclone that the previous owner fitted.
Damien, how have your investigations been going?

[Bear Senior Member Find all posts View Profile Close Bear]

Damien wrote:

I dont think that the 120 V6 uses as an Airflow sensor as such. They are located before the throttle body on the inlet path after the filter to prevent dirt from fouling. I have not seen this on my V6. If its there it must be under the inlet plenum.
I would say they use MAP sensor instead to control the mixture in conjunction with the EGO in the exhaust.
Ensure that your air filter is clean and your tyre pressures are good. Run some injector clean through at your next fuel stop as well.

Replaced the fuel filter, checked the air filter and ran a load of injector clean, all with no improvement.

Today i dropped into Toyota Toowoomba and one of the mechanics came out, showed me the position of the air flow sensor; its a little probe that screws into the top of the air box, just after the air filter. The probe electronically measures the flow rate of air passing it and adjusts the mixture. Mechanic explained that they tend to get dirty and then the motor runs rich and fuel consumption increases - reckons its fairly common. He suggested i unscrew and give it a dose of contact cleaner.

So yes, our v6s do have an air flow sensor ... took a while to find it. Its now been cleaned. I'll provide an update on fuel consumption in a few weeks.

On the side, i was pleasantly surprised at how ready the Toyota guys were to offer help. Especially as i was up front with them that i had not had the vehicle serviced with them ... might do so next time tho.

[Damien Parker Advanced Member Find all posts View Profile Close Damien Parker]

Well there you go!!!!

I haven't been too worried about it of late and have started to see some reasonable figures. I am putting a lot of it down to the wifes heavy right foot. I have seen it in action and its impressive... :lol: :lol:

However, i have been doing some recent experiments on the amount of fuel usage on long trips, and i must say the difference between driving @ 100 Kph as opposed to 110 - 115 Kph is astounding.

I can do the return trip from Newcastle to Sydney using 1/4 of 1 tank Vs half a tank with the higher speed.

I am atributing a lot of this extra consumption at those speeds is due to a higher profile and more weight.

But hey, if all it means is that it takes me an extra 15 - 20 mins over a long drive then its well worth the saving.

[Byrnsie Member Find all posts View Profile Close Byrnsie]

. . . one of the mechanics came out, showed me the position of the air flow sensor; its a little probe that screws into the top of the air box, just after the air filter. The probe electronically measures the flow rate of air passing it and adjusts the mixture. Mechanic explained that they tend to get dirty and then the motor runs rich and fuel consumption increases - reckons its fairly common. He suggested i unscrew and give it a dose of contact cleaner.

Bear

I will be having a go at this tomorrow . . . now that I know what "contact cleaner" is. :shock: I had to do a Google search!
Did come across a couple of similar threads from other sites:

http://www.patrol4x4.com/forum/showthread.php?p=129738

http://www.exploroz.com/Forum/Topic/388 ... aning.aspx

I will let you know if it makes any difference to economy or performance!

Cheers - Byrnsie

[Bear Senior Member Find all posts View Profile Close Bear]

Hey byrnsie, sounds like we are not alone with air flow sensor issues. It will be a while till i know if there is any improvement. Hope yours is a success.
Regards
Bear

[Hutch Addicted PP Member Find all posts View Profile Close Hutch]

At our recent tech day, the guys cleaned a few of these air flow sensor thingy's?? i have no idea though as Peter "pml120r" cleaned it for me.

[JGD Member Find all posts View Profile Close JGD]

Could someone who has removed the sensor confirm that it is held in with the two phillips head screws on top of the air box - like Bear said just past the air filter? Thanks!

[Bear Senior Member Find all posts View Profile Close Bear]

JGD wrote:

Could someone who has removed the sensor confirm that it is held in with the two phillips head screws on top of the air box - like Bear said just past the air filter? Thanks!

That's it. Just make sure you use a smallish phillips. And if you read the couple of links Byrnsie provided, there is a warning not to touch the flat thin metal thingy... apparently (I'm no mechanic) just spray it with PROPER contact cleaner (NOT crc or similar). I found it a very easy job to do ... just a month to find the wretched thing.

Just out of interest, has your fuel consumption also increased?

Hutch wrote:

At our recent tech day, the guys cleaned a few of these air flow sensor thingy's?? i have no idea though as Peter "pml120r" cleaned it for me.

Well, gee whiz Hutch, "I have no idea though". That sure got us informed Makes me wonder how many of us have experienced increased fuel consumption, though.