Really High Fuel Consumption

[Anuradha Neo]

Hi,

I have a Mitsubishi Lancer CK2 (1996) 1500CC/Auto transmission /EFI car whichis in good condition except for the very high fuel consumption, it does about4.5km per liter. I did engine tune-up/ Checked for brake-binding probs. Tune-upguys said engine is tuned well as there is water dripping from the silencer andno white smoke. But still the same.

There is no petrol leak in the fuel pipes/lines, I checked, but there is a bitof a raw petrol smell coming from the silencer.

Pls help me on making this fuel consumption little lower.

Thanks

Edited December 10, 2010 by Anuradha Neo

[VVTi]

Whoa!!! Thats bad! my 3.0 V6 does better than that.

Check your MAF (Mass Air Flow) sensor, the O2 sensor and your crank angle sensor. Is your GB in good condition? Get your injectors cleaned as well.

[Sumiya]

  On 12/10/2010 at 6:08 AM, Anuradha Neo said:

Hi,

I have a Mitsubishi Lancer CK2 (1996) 1500CC/Auto transmition/EFI car which is in good condition except for the very high fuel consumption, it does about 4.5km per liter. I did engine tuneup/ Checked for brake-binding probs. Tuneup guys said engine is tuned well as there is water dripping from the silencer and no white smoke. But still the same.

There is no petrol leak in the fuel pipes/lines, i checked, but there is a bit of a raw petrol slell comming from the silencer.

Pls help me on making this fuel consumption little lower.

Thanks

Hi Anuradha

This fuel figure is too high , means you got unburned fuel from exhaust

there is really something wrong with your O2 or MAF sensor as VVT said,

or setting with your ECU if it is changed when the engine tune up process

thanks

regards

sumith

[Anuradha Neo]

Hi,Thanks for your quick replies.

I doubted that it couldbe perhaps the O2 sensor, but I never knew about the MAF sensor and don'tknow whether my car has a MAF either ! Is there any good place (garage or some person) thatyou know where I can check these sensors and replace if needed?

But the garage guy saidif there is unburnt petrol blowing out of the silencer there should be a whitesmoke, so that’s why I assumed that its not possible of unburnt fuel.

Thanks a lot guys forthe help

[Sumiya]

  On 12/10/2010 at 8:27 AM, Anuradha Neo said:

Hi,Thanks for your quick replies.

But the garage guy saidif there is unburnt petrol blowing out of the silencer there should be a whitesmoke, so that’s why I assumed that its not possible of unburnt fuel.

Thanks a lot guys forthe help

nope

if it is White Smoke , probably coolant or water in the exhaust , usually unburned fuel

cause smelling through exhaust, which may possible be faulty o2 sensor in your situation

or bad air fuel mixture through ECU module settings

thanks

regards

sumith

[Pericles]

Sound like the issue is not your engine. I'd check the tires, the gearbox and then the drive train in general.

Or its your driving style/habits. For example, do you keep it parked with the engine running to keep the A/C on? Rev really high when driving? That sorta thing?

[Anuradha Neo]

  On 12/10/2010 at 9:18 AM, Pericles said:

Sound like the issue is not your engine. I'd check the tires, the gearbox and then the drive train in general.

Or its your driving style/habits. For example, do you keep it parked with the engine running to keep the A/C on? Rev really high when driving? That sorta thing?

Nope, I tried changing my driving style in many ways, didn’t work.Nor I reverse fast or park with A/C on. Fuelmeter arm goes down as I’m looking at it. There is something wrong as there is rawpetrol smoke, this is not normal. Im so disappointed about this, maybe I shouldchange the O2 and see.

[Ripper]

yeah...unburnt fuel ends up making black smoke...

i've had it for a few days when the knock sensor got disconnected making the ECU get all confused! Very poor economy too...

But that error of course threw an error code with the check engine light...

Like many say...my guess too would be an issue with a sensor somewhere...

Or the very rare possibility of ECU malfunction...Sometimes when that goes it wont make the engine light come on

[Anuradha Neo]

  On 12/10/2010 at 9:02 AM, Sumiya said:

nope

if it is White Smoke , probably coolant or water in the exhaust , usually unburned fuel

cause smelling through exhaust, which may possible be faulty o2 sensor in your situation

or bad air fuel mixture through ECU module settings

thanks

regards

sumith

Hi, just to know I'm asking...

is it possible to change/adjust the ECU module settings ??

Thanks

[Sumiya]

  On 12/10/2010 at 9:41 AM, Anuradha Neo said:

Hi, just to know I'm asking...

is it possible to change/adjust the ECU module settings ??

Thanks

hi

Not automatically unless some one physically change them

there are some situation they reset there value in an electrical FAILURE

thanks

regards

sumith

[VVTi]

First of all, change you garage. A mechanic who says white smoke = unburnt fuel should be shot immediately.

Have you checked you plugs? Is there a miss? Like Peri said, is your tyres Ok, are your breaks binding? Before you even consider an ECU change, check the basics. It could be a vacuum hose that is broken, disconnected or cracked.

Over the weekend, park the car in a well lit area and go through the engine bay to see if the are any loose wires hoses.

[jdnet]

  On 12/10/2010 at 11:41 AM, VVTi said:

Have you checked you plugs? Is there a miss? Like Peri said, is your tyres Ok, are your breaks binding? Before you even consider an ECU change, check the basics. It could be a vacuum hose that is broken, disconnected or cracked.

I'm going to have to agree with VVTI. You may want to check your plugs and make sure you have the correct ones. A plug with the wrong heat range would cause the problems you described. On my tribute at the moment I have the wrong plugs and can really smell the gas at start up.

[hakjay]

why not take it to the agnets for a full check on the system. they use the "MUT" unit.

[timmy]

If it helps, I own a CK2 as well (its an MX Extra) with the same spec you mentioned. I dont get a fuel mileage of more than 7.8 kmpl city driving. But outstation it does about 11 - 12 kmpl. You cant expect much from a car like this. But the fuel mileage you reported is certainly due to a prob in your engine I would say.

My car also had brake binding issues and I remember the mileage figures dropping to about 5-6 kmpl. Once I got it sorted out the mileage rose again to the standard 7.8. I got a tuneup done from UM when I bought this car. They changed plugs and did a cleanup. The MUT didnt read any errors and it was mostly in Japanese. But I still do get that unburnt smell from the exhaust but I want to leave it at that, cos knowing trying to figure out the problem I would have to spend more money than the savings I could get from it.

[The Don]

Few things to check. First of all the idle control valve have a habit of failing in these cars and some mechanics just advance the engine to compensate. Check if this is not the case (its attached to the throttle body on the side and there is information on the net to check if this is working or not. A good indicator is that either the engine starts to knock when the AC is turned on or is idling too high).

Second and more likely candidate is the oxygen sensors ! They require replacement every 100k miles

Check the plugs and see if you've got the correct plugs. The genuine mitsubishi plugs being sold in the market does not suite every mitsubishi engine. Find your engine type and get the correct part number from the NGK web site.

[tom]

  On 12/10/2010 at 11:41 AM, VVTi said:

First of all, change you garage. A mechanic who says white smoke = unburnt fuel should be shot immediately.

Have you checked you plugs? Is there a miss? Like Peri said, is your tyres Ok, are your breaks binding? Before you even consider an ECU change, check the basics. It could be a vacuum hose that is broken, disconnected or cracked.

I have a Mazda BJ5p 2001 model and have the same issue with Fuel. Chekced all the things including plugs, tyres, ATF, breaks,trottle body, idle control valve etc. But no luck. still it is doing only 6.7 Km/Ltr.

but didnt check the sensors yet.

Can you recommend a Good garage?

[Shehan Niyas Wildchild]

seems you have worn dripping injectors and or bad timing or distributor alignment..

[k9master]

  On 12/10/2010 at 11:41 AM, VVTi said:

First of all, change you garage. A mechanic who says white smoke = unburnt fuel should be shot immediately.

+1 Was about to suggest that myself...

I don't know how these mechanics survive...