Excessive Fuel Consumption - 1.5 1NZ- Engine

[tnr18]

Hi,

I've been getting poor gas mileage on my 2007 1.5 1NZ Corolla. When I use Super I get and average of 21MPG and with Premium 25MPG and overall average per tank of 228 miles (about 367KM).

Toyota clean and serviced the throttle body twice and when a scan was done it came up with;OXYGEN SENSOR NO.2 READING HIGH [99.15%]. Toyota cleaned the carbon buildup on the sensor and cleared the code. However, the fuel consumption has not improved.

Does anyone have any ideas on how to resolve this problem?

[Swifted]

what fuel are you using now? that shiddy red dye NP puts in the Super has been known to block Injectors & foul O2 Sensors. I'd say check and make sure your Air Filter is clean, check the spark plugs (replace if unsure of age) -> run a 0.044" Plug gap and see if that helps.

[Big Z]

Im interested in finding out how they serviced the throttle body.
Did they remove it from the vehicle?
What mileage are you doing?
Im guessing that its a local. (means it has an accelerator cable)
have you serviced your injectors?
have you cleaned you air flow sensor?
i have a 2007 from the firm, and she runs like a charm.

[M_2NR]

we have a 2008 NZE141 with the 1NZ-FE and we get around 350km as well.

Didnt realize that was bad

[gt4tified]

Go weigh your foot and make sure it didn't get heavier.

[pugboy]

I have a 2006 fielder NZE and get at least 450-500km to tank refilling back about $115 or so. Driving with a/c on and around 110kph and lots stop/go.
I have squeezed almost 600km once by driving a lot slower and without a/c

If you are using cheap plugs, switch to iridium you will get at least 80km more per tank.

[Big Z]

For reference, $100 super gives 450 km on my Corolla.
Only non-standard item is the KN drop in filter.

[tnr18]

Big Z - To answer some of your questions; Yes the car is a local (2007) and is stock so no modifications made and I get on average 370KM for $115.00. They didn't remove the throttle body from the vehicle, I think they just sprayed it with a cleaner. The car is doing 55000KM right now. The injectors were physically removed from the vehicle and serviced at least that's what Toyota Service in south said. They also cleaned the air flow sensor but I'm not sure how it was done. If all this was done then it should be running great but the reality is... not really.

pugboy - Mine is a local 2007 and I use the plugs that Toyota recommends and change when they do the service.

gt4tified - You are suggesting I drive at excessive speeds but maybe you haven't been on the roads of T&T lately because it's difficult to exceed 100KM/hr with the thick morning traffic. The average speed I maintain is between 80-100Km/hr.

corolla_2nr - It is bad I dropped it off at Toyota Barataria yesterday for their specialist to do an evaluation and report on his findings.

Swifted - I'm using "Super" right now. Toyota when they did a check one of the O2 sensors came up with a code. They cleaned the carbon buildup on it and cleared the code as the fix. The air filter and spark plugs were replaced at the last service.

I think after I get back the car from the Barataria branch of Toyota I'll need to get a mechanic. Maybe you all can advise accordingly but I'll let everyone know how it turns out after this latest development. I should have word by Saturday. Thanks everyone.

[Hook]

I would LOVE to know how they "cleaned" baked-on carbon build-up from an O2 sensor.
If you understand how it got deposited there, you'll know there's no solvent ever invented that can clean it.

And the fact that a supposedly self-cleaning heated sensor had carbon build-up in the first place, means your overfueling problem CAUSED the sensor to become like that and NOT the other way around.

I know it goes against your warranty, but stealerships here aren't particularly renowned for doing what you paid for (I've seen pitch black oil and a siezed filter the day after a supposed oil change on a local Lancer wagon that had been going to the firm religiously for servicin since it was bought from them), so I wouldn't take their word for it.

If you can, have a good mechanic check plugs, air filter, clean the injectors and physically inspect the O2 sensor without making it look like u tampered with anything and check the difference in your economy.

[tnr18]

Hook - I just took their word for it because I'm not very savvy when it comes to vehicle maintenance. I guess based on your explanation I can strengthen my argument when I have my next conversation with them. The warranty is coming to a close in August of this year so i won't be taking the vehicle back to them for servicing. The thing I have been tracking and documenting the worsening situation and when I mentioned to the Service Manager his body language showed some concern as if to say; how did they arrive at that explanation? Well I'll let you know how things develop once I get back the car and if you have a good mechanic in mind e-mail me the information please.

[tnr18]

So I just got the call from Toyota, all the sensors are operating within their designed parameters based on the reading from the ECU test. If everything checks out then I'm not sure what else to look at that might explain the excessive fuel consumption. They asked about the tires which are 215/60/14 Nexen and I've been using these from the very day I got the car when I changed out the bicycle tires the car came with.

[Hook]

PM the author of this thread and find out what he did to solve his problem...I ain't reading through all of that.

http://forums.trinituner.com/forums/vie ... hp?t=71295

[tnr18]

Ok folks, so I got back the car from TTTL on Saturday and as expected they indicated that all sensors are operating within normal parameters and their checks revealed nothing wrong with the vehicle.

Once again they physically removed the injectors and cleaned them (I have to take their word for it) and said I should monitor the consumption. Bear in mind this was done only a month or so before with no real improvements. Then they tried to say that my tires are part of the problem to which I protested because from the day I bought the car and I mean the very day, I replaced the tires with 215/60/14 Nexen. So that argument was out of the question. Not sure what to do next.

Hook - I reviewed most of the posts from the link you pasted and the guy is having the same problem as me but there was no solution. Thanks a million though there are some things I might try like changing the plugs, filter, etc...

[tyreplanet.com]

Ok folks, so I got back the car from TTTL on Saturday and as expected they indicated that all sensors are operating within normal parameters and their checks revealed nothing wrong with the vehicle.

Once again they physically removed the injectors and cleaned them (I have to take their word for it) and said I should monitor the consumption. Bear in mind this was done only a month or so before with no real improvements. Then they tried to say that my tires are part of the problem to which I protested because from the day I bought the car and I mean the very day, I replaced the tires with 215/60/14 Nexen. So that argument was out of the question. Not sure what to do next.

Hook - I reviewed most of the posts from the link you pasted and the guy is having the same problem as me but there was no solution. Thanks a million though there are some things I might try like changing the plugs, filter, etc...

what size tyres the car originally come with?
they prolly givin u some BS about the injector cleaning or they using some cheap solvent, i would recommend u do a proper injector cleaning, oil and filter change (what body oil u using?), air filter change and change of plugs ... a service like that would run you around 600 you could check our site for more details about the fuel injector cleaning

[tnr18]

tyreplanet.com - The care originally cam with 185/60/14 Yokohama tires. I'm not sure what body of oil is used, I just drop the car off for service. I know the air filter is changed every 10,000KM and the oil filter every 5,000KM, the plugs used are what ever TTTL recommends. The warranty comes to an end in August this year so I'll be looking for a good service outlet to do the maintenance on the vehicle or I may very well just sell the car. Thanks for your advice and help though, I'll check the website.

[tyreplanet.com]

tyreplanet.com - The care originally cam with 185/60/14 Yokohama tires. I'm not sure what body of oil is used, I just drop the car off for service. I know the air filter is changed every 10,000KM and the oil filter every 5,000KM, the plugs used are what ever TTTL recommends. The warranty comes to an end in August this year so I'll be looking for a good service outlet to do the maintenance on the vehicle or I may very well just sell the car. Thanks for your advice and help though, I'll check the website.

185/60R14 and 215/60R14 has a difference of 5.8% .... when changing tyre sizes it's recommended to stay within 3% difference for proper braking and handling.
as these tyres are in fact bigger by 2.8% it would put more strain on your drive train and suspension which could lead to problems that you are describing. However i think this isn't the case... have you experienced any suspension problems, especially at the front end? are you still using pumping "super" into your tank ?

[Civic Dude]

ok..let me add my 2 cents here.. ( dont let the name Civic dude change anything as i have both toyota and honda right now )

I have RORO 2003 NZE with a 1.6L 3zz Vvti engine

I change oil every 4500 to 5000 km.. using Castrol GTX 20W/50. Using the regular white paper Sakura air filter ( which I dont change too often )

My tires were 185/50/14 then 205/60/14 and now 205/45/16 with no noticeable difference gas consumption.

My Plugs are NGK Iridium

I use both Super and Premium gas for no special reasons and mixed at no special combinations. sometimes may be a complete tank of Super or Premium

I drive from gasparillo to Piarco and have lots of other running to do..i do on an average .. every oil change 4500km in approx 6 weeks. My average speed on the hiway is 130km to 160km with a/c on at 98% times

my car averages most times to give me approx 450 to 525 km per tank depending on my use.. some times i might be chillin with the car and leave it on idle for approx to an hour just for the ac.

btw.. the air flow meter can be cleaned by using any carb spray.. u just take it off and spray the metal parts clean..let it dry and replace it

as far as I know.. an O2 sensor cannot be cleaned.. it has to be replaced if the reading is not acceptable.


MY advice to u tnr18 is you dont just drop your car off to service and pick it up without knowing EXACTLY what is done on your car AND the reasons !.. you are operating like a rich papi with paper to burn.. then u wanna be wondering why your car is guzzling gas. Wise up and know who is doing what to your ride dude !

[Hook]

^^^ yooz ah cool tess...I like what u sayin' meng

Point to note on cleaning the AFM: Do it like first thing in the morning when it's stone cold. If you run the engine at all and it gets warm, you run the risk of the insides "sweating" on the internal electronic components...that's all.

But you're saying the same thing I was saying all along, the firm always has a way of making it look like they're working when they aren't, so I say take it to another mechanic who can clean, inspect and tune-up the engine properly (without it looking like it was tampered with to avoid warranty issues), and then monitor the difference in the fuel consumption.

I could never see a change in tyre size causing a 100km reduction to a full tank. He needs to get it checked out by someone NOT in the firm.

[heshere2001]

Hi!

Welcome to the club. The most I have got from my 1NZ is about 397 and that's with light driving and some redline I think.

There are claims of 400 - 500 km for this engine but alas....

Maybe the foreign used owners have a bigger tank? I think local corollas are 25 liters?

I guess I'll check my O2 sensor as well.

Edit: Oh and if you are interested, my personal mechanic is one from Toyota. So if you need a guy pm me and I'll ask him.

[pugboy]

well best thing is to try changing the O2 sensor

I don't know how the company can say that they checked the parameters of the O2 sensor.
to check that they would have to check the exhaust emissions to see how much unburnt fuel is in it, go figure if they have capability to do that by capturing the gases and put some kind of analysis on it

[Hook]

@ how before de man get a proper tune-up people jump to suggest changing expensive ass sensors!
He doesn't even know if he's getting what he paid for from the firm or if they're just bullshitting him.

Best thing is to get it properly serviced and monitor it from there.

And then this other guy's getting the same problem but he uses a mechanic who works at the same firm but does private work
Common factor? TTTL MECHANICS!

tnr18, what is your location?

[heshere2001]

^^ I think not. Done loads of work by him from my uncle's Cressida to my Dad's KE to my nze. Always honest. Always good work.

[Hook]

That's great, but I stand by my statement. You admitted to having the same problem in a similar vehicle and a TTTL mechanic is addressing the issue without success. Take from that what you may, but from these two cases, TTTL mechanics don't appear to know what to do about this problem.
It's either that or you two just happen to get two NZE Corollas with some sort of factory defect.

[Civic Dude]

To the guys who may think that the gas tank size may vary.. try another way to monitor your gas consumption.. its the way i monitor my car all the time.

when you FULL your tank.. zero the odometer. you have two trip sets for the odo.

run the car to at least 300km to get a good average of consumption and then refill .. check your odo and check the number of litres that the tank used at the pump.

when you do the math.. if your car is giving you approx 10 to 11.5 km per litre .. you are good to go ...

[tnr18]

Hi everyone well I ran down a tank of super to the fuel light after getting back the car from TTTL, who kept it for a couple of days to evaluate it. The end result is the same, I got 379KM @ $115.00 to the tank.

Civic Dude - Yuh boy is not a big Papi, I'm just a bit limited when it comes to the mechanics of my car and because it was a new purchase I just trust the "good people" at TTTL to manage the maintenance. Based on most everyone's comments I guess it's not the wisest thing . Anyway I do have all the details of what is done to the vehicle during service but you'd appreciate in some instances I can't verify some of the items because of the nature of the task carried out. However, I review the work sheet and I have every single one so items that continue to exist after my warranty expires in August will stii be valid for addressing....I hope. Also I have a spreadsheet that I've been using to monitor my fuel consumption since the problem surfaced. I have bot "Super" & "Premium" scenarios and the average 22MPG Super and 25MPG Premium.

Hook - If you have a good mechanic that can have a look at the car e-mail me and maybe we can get an independent evaluation and possibly a solution to this problem. I'm located in Marabella but I have no objections to going anywhere to get the problem resolved.

pugboy - They stuck an emission tester in the tail pipe and measured the mixture at the tail pipe and it came up as being somewhat balanced. Every reading on the scan showed all sensors operating within defined parameters. So I'm at a lost as to why the car is making such poor mileage.

[pugboy]

if its still under warranty you better write them a letter stating the facts which are quite clear
they cannot dispute that 1nz's get much better mileage in general

[tnr18]

pugboy - I've already written a comprehensive document outlining the challenges with the vehicle and attached all the service sheets. they have admitted to the poor mileage but have committed to reviewing the case after I've completed the tank of fuel. I have to e-mail them the mileage so on Monday they will have to come up with some solution. I'll get Customer Service involved so that it's followed up.[/b]

[tyreplanet.com]

i fall in late ... sorry guys been real busy

@Hook - changing tire sizes out of manufacturer specs affects correct reading on the ODO

http://www.1010tires.com/tiresizecalculator.asp

[trouble]

I am reading through these posts & wondering if my gas consumption in my NZE is good. Can you tuners please advise? These details are listed below:

Model: 2005 local nze
Engine: 1.5L 1nz-fe
Mods: Denzo Iridium plugs & Drop-In K & N filter
Tire size: 215/35/18
Gas consumption: 415-420km/tank of super gas with a/c, usually takes $100-110 to full up from empty (gas light on)

[Hook]

So okay, to recap:
Stock tyres: 185/60/14

pugboy, 2006 1.5L NZE Fielder, 195/65/15, DD=9.0% - 450km-500km
Big Z, (2007 Corolla?) engine and tyres not specified - 450km
corolla_2nr, (2008 NZE141?) engine and tyres not specified - 350km
Civic Dude, 1.6L RORO NZE, 205/45/16, DD=2.2% - 450km-525km
tnr18, 1.5L, local NZE, 215/60/14, DD=5.8%- 370km
trouble, 1.5L, local NZE, 215/35/18, DD=4.9% - 415km-420km

What does this tell us?