Fuel consumption

Hi there

Wondering if anyone can answer me this one. I recently bought an imported mitsubishi legnum 2.4GDI from Japan, into New Zealand and overall the car is very f**kin cool, but the fuel economy of the car is outrageous i mean I fill the tank 55Litres and I get 380Kms max out of it. Now I have read some info about the high sulphur that we have in New Zealand and that I will need a low sulphur fuel like they have in Japan which is 10-15ppm and in NZ the fuel I have been using is 91octane which has 500+ppm. Does anyone know what the problem is as the garage has checked the car over and says that everything is ok. I have contacted BP and there Ultimate fuel only has 50ppm which is the closest thing to Japanese fuels.

Thanks D

Hey,

I have a 1997 Galant VRG GDI 1.8 4wd. Im also having fuel problems as well as oil comsuption. What I know is that the air to fuel ratio is way off. Pumps more gas than it should, the gas doesnt burn completely and it sticks to the cylinder and mixes with the oil. Thats the oil consumption problem, as for the gas im still checking the O2 sensor and anything else that might make this problem go away. I have a GDI repair manual in English if you are interested, uf you have any answers or anything that might help me out please let me know. Thanx

hey where did you get the manual from nando210
they are meant to run lean at cruise but either the fuel is bad or the sensors are wrong in the engine it doesnt seem to work,some people say its cause they get carboned up others say its bad injectors but no one seems to know for sure
personally i think the gdi is a badly designed motor that was released onto the market to soon
but im stuck with mine pitty cause the rest of the car im happy with
does yours sound like a tractor(noisey lifters)
let me know if you had had any help from anyone.
I was going to replace the injectors but at Nz$450 each i changed my mind apparently they dont last this is what might be causing the shudder(running out of gas feeling)mine does it real bad to the point i put a resistor on the temp sensor so it wont go into lean burn at least the car is better to drive also had to put a sensor in for the fan as the car now thinks its running cold
no one knows nothing about these cars in new zealand
cheers stu

Hey Stu, is good to hear from someone that has the same car trouble as me. My car does the same thing, it shudders and sometimes its stalls.
The gas here in Peru is pretty bad 97 oct is the highest one can get.
My lambda sensors are fine... i had them both checked. My injector are fine as well. I think my problem has more to do with what you are talking about. Can you please explain what kind of mods did you do to your sensors??
I got the manual online, its like 11 megs so i cant post it here. Tell me another way. The car is great but i cant stand the engine anymore, i think i might have to sell it soon. Hope to hear from you soon,

Nando

its not the ideal way of solving the problem of the surging
you just cut the wire from the temp sensor on the right hand side of the block under the fuek injector pump i used a variable resistor i cant remember the size it needs to be
then you cut the small wire going to the control unit on the fan and i got a heat switch thing from a plumber mate (goes on a gas heater as a saftey switch i beleive)witch turns the fan on when the radiator hose gets to about 80degC
i had my injectors cleaned and they said they were fine aswell but still think they are at fault cause thats the feeling you get when running out of gas which is what happens if the injectors are stuffed they dont atomise the fuel crroectly which in these is engine i beleive to be very important
have to tried contacting mitsubishi japan or anything regarding thes problems. We cant be the only 2 with this sort of problem i reckon that mitsubishi has alot to answer letting these crap motors out of the factory in the first place and also they say hopw great they are.

ok...so what you are telling me is that the lean burn mode depends on the temp sensor?? how so??
and hows does it help the engine to trick it into thinking is runnig cold.
The carbon build up is bad, i had mine cleaned last month. Does your car burn oil???

ok cause the car thinks its cold it doesnt use the lean burn like when you first strt the car on a cold morning its only once the car is warmed up it goes into the lean burn mode at between 2500 rpm and 3500 rpm from memory .Once the resistor is in place it runs slightly richer i found that the fuel usage actually went down slightly after this i guess cause the car just runs that bit smoother
one other thing is i have hose connected to the intake sucking a small amount of injector cleaner sucking into the intake in the hope it cleans the back of the valave seems to work stops some of the noisey tappets which is also caused by the carbon build up
if i could find where the egr valve was i would block that off aswell but as i dont have a manual i dont want to go pulling the whole engine apart as i need the car everyday i havent done that yet
so if you can send me the page of where that is i would be thankfull you are the first person i have found that has a manual i tried the jerks at the dealership here but cause my car was a used jap import they dont want to help me

the oil yeah it does a little
seems to be better if i use deisel oil
try different brands of oil and different grades some dont seem to be as bad as others
i have never had the head off to clean carbon off only put cleaner into intake

OK... i did something like that, i took the termoswitch out, so that the ECU would think that the car is always cold. Didnt work... i had worse mileage. Im going to try your way.
What kind of diesel oil do u use???
UI dont have the site of where i donwloaded the file, maybe we could try MSN??

yip my msn hotmail account is stustunz@hotmail.com
when you cut the wire it would have told the ecu there was a fault did the engine managment light come on one other thing you will have to adjust the throatle position sensor once you have put the resister in series with the temp sensor (i used a resistor wheel to figure it out what resistor to use from a place called dick smith bit like radio shack in america electronics store)took a while to get a place that was right the only problem i have found with doing this is that if you leave the car idling with air con on it will start to hunt,and occastionally idles a bit funny either high or really low.But probabaly would have done strange things like that anyway mitsubishis seem to be bad with engines alround really they always use oil and they always have noisey lifters.the oild i used was just castrol diesel oil (diesel oil has more detergent in it which helps keep it clean and cause these motors seem to dirty the oil very quickly it seems to help a bit.one other thought a car can carbon up from running lean aswell sounds strange but if a car is miss firing from running to lean then the incomplete combustion will cause carbon i dont know weather this is what can cause them to carbon up aswell but i have found the car better to drive since putting in the resistor.I use the car for carrying my work gear arround so it is always loaded up so the miliage is never going to be that good anyway plus been 4wd 1800 is probabaly a bit small for the size of the car.ONe other thing i noticed is that if i use Bp gas i get alot less kms per tank than if i use caltex(texico i think is the same)i get about 500km/50letres of gas no where near what they reckon i should but before i put the resistor in i was probably struggling to get 400-430 sometimes and with the surging it was a piss off to drive

holly shit, just read this thread and now iknow i'm not alone. I just picked up a used Jap import legnum 1.8 st gdi and after the first few tank fills, i thought, where did all that gas go?...I'm using the bp stuff (91 oct as supplied in NZ) and have been averaging about 380km/55l...shit thats about 13l/100k!!!I get piss poor performance with the poor fuel econ....now i'm wondering how to fix this thing (or just sell it). Was planning to send it into the local mitsi dealer for a service, but now im starting to wonder if they will know whats going on!
I just changed the oil the other night and, shit, the fumes coming off it could almost be that if straight petrol....theres definately something wrong going on here. A manual I hear you say...now that could be interesting reading hint...hint!

for a start mega the cars are designed to run on 100octane no sulpur gas which we dont have in new zealand meaning these cars will never run right in NZ using caltex gas high octane helps a little bp gas is the worst out of any.and you are correct in saying taking it to the mitsi dealer wont help they are just dickheads with no idea, id say selling it would be your best bet but depends if you want to wish this on someone else did you buy from a dealer
if so you could try getting your money back cause believe me they just worse

You´re right mega.... you´re not alone. I´ve tried everything, mitsi dealer dont know shit, sometimes i thikn i know more than them. I found a buyer for my car, im going to loose some money but i dont want a car thats going to give me trouble. The manual i have is good, but its for the GDI 2.0 engine, it helps a lot actually even though they are not the same displacement. THe basics are the same. You guys have to be very carefull, you cant use bad gas, you can wreck the sensors, gas pumps and injectors. I have a freind that did so and he has his car sitting on his driveway for about 6 months now. THe only thing i have to say...... is SELL......

hey nando got your thing on msn so will chat to you on there when i see you on dont know the time difference so i hope to catch you online soon

Hi stu/nando

thanks for the replies, the info has been very informative. Just for interest, i had a quick chat to the local mitsi dealer and explained the problem. Their reply was as follows:

"Hate to say this but a tune up won't fix your problem. A rough idea for costs
is $1800.00 for a fuel pump $600.00 for injectors and 1200.00 for a decarb" - (nz dollars)

Some how i think you suspusions on their advice may be correct. They seemed to be treating this matter as a form of income as oppose to servicing their clients. I can tell you one thing, this is my first and probably last mitsi purchase....and i will be sure to share my opinions where ever possible!

I'll give the caltex stuff a go for the mean time and see how i go.

Anyone out there after a cheap mitsi! ;)

mega i had a new fuel pump fitted and injectors cleaned when i first got the car that chaged jake shit.
An update on what i have done after last week and talking on here i decided to block off the egr valve. well bugger me ye ha i just got 555km out of a tank of gas and it still has some gas in the tank so id say i should get around 580 to 600 as compared to 480 to 500 i was getting so im pretty damn happy.
(this is with a resistor in the temperature sender unit and thermo switch for the fan as the ecu normally controls this)with the egr valve blocked off no more noisey lifter cause this is what cloggs the backs of the valves causing the noisey lifters)
IF you would like pics or any more info im happy to let you know what i have done as this has caused me alot of anger in the past 2 yrs that i have owned the car.
Cheers Stu

Hey Stu, what you have suggested is of interest to me. Though one has owned the car for a short duration, I'm sure your 2 years of pain and experience is something i'm not willing to endure myself. What do you feel has made the most significant improvement? I'm guessing the variable resistor....excuse my ignorance, but could you explain the function of the erg valve?
550km/tank seems a lot better than the 380 im getting at the moment.
Pics would be great, I'll try and send you my email address via the detail on your profile

Cheers
Dennis

Dont even think of using 91 oct petrol, it may sound a bit simple but I would go straight to the petrol station and full it up with 96+, GDi engines hate low octain.
If fuel consumption is your only problem consider yourself lucky, they have many many more problems than that. atleast yours is a runner.

ok cause the car thinks its cold it doesnt use the lean burn like when you first strt the car on a cold morning its only once the car is warmed up it goes into the lean burn mode at between 2500 rpm and 3500 rpm from memory .Once the resistor is in place it runs slightly richer i found that the fuel usage actually went down slightly after this i guess cause the car just runs that bit smoother
one other thing is i have hose connected to the intake sucking a small amount of injector cleaner sucking into the intake in the hope it cleans the back of the valave seems to work stops some of the noisey tappets which is also caused by the carbon build up
if i could find where the egr valve was i would block that off aswell but as i dont have a manual i dont want to go pulling the whole engine apart as i need the car everyday i havent done that yet
so if you can send me the page of where that is i would be thankfull you are the first person i have found that has a manual i tried the jerks at the dealership here but cause my car was a used jap import they dont want to help me

How do you make it run richer when it has an 02 sensor? doesn't it just correct the mixture, maybe you are putting it into "fail safe" and it's just running in open loop, unplug the air-fow meter and see if it does the same

REPLY TO ALL

Do you all realy think that the New Zealand dealerships/service agents should be able to repair a product they dont actualy sell? without manuals? simply because it has a the name Mitsubishi on it? Try buying a cellphone in Japan and then ask Telecom why it doesn't work here, you wont get it fixed, the will just tell you you have to buy a new one.
The GDi engine isn't a bad engine, we just dont have the fuel to run it correctly.

So who's to blame?

Government: For allowing the imports?
Importer: For importing?
Service Technician: Not knowing a forign product?
Oil Company's: For not supplying high quality fuel?
Owner: Buying the car?

CAVEAT EMPTOR

hey guys i thought it was just my car with these problems and it was really getting to me but now i know im not alone it makes me feel a bit beta bout it all. I hate my noisy lifters anyone know how to solve this? have only had the car a couple of weeks and i luv it but after reading these posts now im not to sure. Im gona try sum desiel oil as someone had sugested. Do u think an addidtive would help? Not sure where abouts u guys are from but im in palmy and can get 98octane from Bp here but someone had recomended caltex which would be beta 98 from bp or 96 from caltex? Any help would be great and as for that resistor and making the engine run lean/rich watever i think i leave it sounds a bit tech for me not to familiar with the motor yet. :banghead:

Hi all just a reply to what has been said

i have monitored the o2 sensor it does what it is meant to do the resistor just tells thecomputer the engine is still cold unplugging the airflow meter sends the car into limp mode as anyone would know
the resistor DOES NOT put car into limp mode
the o2 sensor swings back and fourth as it should do .2to .8volts or higher or lower depending on where and how you are driving

the car will run richer cause it thinks its cold and that is how they are programed to work instead of a choke in a carbi they run richer which is what choke does

Hey Waatz do you even know how these engines operate and did you own one or what problems are you talking about ?

By the way im just trying to work around a problem i and other people have so if anyone else knows how to change other setting on the ecu or airflow meter or any other sensors or solutions they have come up with let me know

Cheers Stu

Basically, If its buggered your stuffed.

When I got my 1.8L GDI, there were prettymuch all the problems mentioned here. Fortunatly because I got it from a dealer, I was able to take it back and make them fix it.

At least i [thought] they fixed it. The had it for about a month, then sent it to mitsubishi for another month.
Eventially I got it back and they had fixed the random stalling at idle and the car seemed to idle a little better.

Fuel economy was still crap.

Later I took it to my mechanic who got the EGR valve, manifold and injectors cleaned.
Ran a bit better, but still crap fuel economy.

Best economy I have had is 10KM/L (10L per 100KM)

I am following the same path as Stu... Making modifications and monitoring the fuel consumption and idle characteristics.

Im currently playing with the EGR and will see what that does to the fuel economy.

Hey Stu, did you block the EGR inlet, or disconnect the solinoids (or whatever they are) that control the flow to the manifold?

might as well ditch as much of the emissions crap as poss, then if there is an improvement work backwards to see whats screwing it up.

Hey Nando, I would be REAL keen to get a look at that GDI repair manual...

Cheers,
Ken

Hi guys,

I am considering buying a Legnum in the next few weeks and this thread has certainly been very interesting to read.

Would you say that this car is good even though its a bit thirsty - would you get one again know what you do now?

Have you guys made any more progress on getting better fuel efficiency - I'm really interested on how you go.

I love the look of this car and want to get a 2.4L version.

Cheers,

Jatz

Well, I blocked the EGR at the engine... Made a small plate out of aluminum and bolted it in place.

I also took the manifold to bits (well, as many bits as you can) and gave it a good water blasting to get rid of as much carbon build up as poss. Have run nearly 1/2 a tank through it, and reackon ill get to 400km on this tank.
1.8 GDI doing max 400km to 45-50L of gas... OUCH
I'll have better data when I have run a full tank through.

Jatz, if you can I would get a good test drive first. Then make up your own mind. See if you can get a demo for the night or something, then take it for a good long drive. I'm sure you wouldn't forget to thrash the hell out of it ;)
I must say i'm also not that impressed with the tiptronic gearbox eithier, i'm definatly going manual when I get rid of this piece of crap.

I would avoid GDI if you can... Not worth the potential problems.

Cheers,
Ken

Thanks Ken, I was thinking of getting a manual - lighter car, more fun and less to go wrong.
I wonder if the 2L or 2.5L non-GDI motors have the same fuel consumption probs as the GDI.
J

I doubt it. You would just get a "standard" fuel consumption I suppose. Also depends on how you drive.
I guess with GDI you either get awsome fuel economy, or absolute crap. The potential savings on fuel is pretty impressive with GDI, but whats the point if you cant gaurentee you gonna get it?

I think i'll ditch my GDI and get a VR4. Then at least if I use heaps of gas its because im going fast. I wouldn't mind having crap fuel economy if the engine was powerful, but when you doing 8.5km/L round town in a 1.8 there is something seriously wrong.

I don't know about the GDI.

The 2.5 V6 in standard and twin turbo form I do know.

The twin turbo needs high octane petrol, 97+, using 95 can drop power by about 40 bhp. This is an ecu issue - I don't know how, but it modifies the way the engine runs depending on the octane of the fuel it is using. This is an estate car which gives a lot of fun for the money. I used to get 200 miles on 45-50 litres.

The standard V6 is smooth and responsive. Good torque, reasonable power. I believe still a good car, but the handling is less sharp and the ride MUCH softer than the VR4. I currently get around 300 miles for 45-50 litres.

Incidentally, the INVECS II transmission was developed from a porsche box. Most people consider it to be a very good auto. (I had one - would rather have a manual!) Surely if it is that bad, then you should be wondering if you have a problem with that too? I am on my third Galant estate and I have had no technical issues apart from the now recalled ball joint problem.

Sorry this doesn't solve the GDI problems out there - maybe it will help restore some faith in the galant range, though!

I must admit that my viewpoint on gearbox type is rather biased. I would rather just have a manual full stop. Im probably a control freak who needs to feel like he is telling the car what to do all the time.

It is all reall rather irrelivant to me now... I just traded the GDI and got a 2002 Legnum VR4 Manual

Had it a couple of days now, and HELL IM IMPRESSED. Gotta get me a radar detector though, else im gonna loose the 5 points (out of 100) I have left on my license. :P

Spent yesterday (4:30pm - 9:30pm) installing my sustec pro coilovers and my alarm system. Well, at least most of the alarm system... Enough to demobilise the car so its still there when I get outta work.

With the suspension in, the handling is VERY sharp. an amazing difference actually.

I guess ill have to measure the height to make sure its all legal.

How do you drive for that fuel economy? I don't expect my first few tanks of gas to last long, I keep hitting the gas to see how hard it pulls ;)

300 miles for 50L is better mileage than my 1.8GDI! I used to to get maybe 250... And that was with NO power.

VR4, eh? Check out www.clubvr4.com as that's the place to be with that car. You won't get 300 miles with the turbos. 200 if you drive nicely.

Thanks. I checked them out and registered for their forums.

I went for a thrash today, got 190 miles (just over 300km) out of 30L of gas... I was pretty stoked. thats better mileage than my 1.8 GDI.

was probably 1/2 highway driving, 1/2 high rpm thashing.

OK, I was seriously thinking of buying a 1.8 GDi (2WD) wagon, based on the fact that a friend got about 400km on less than 1/2 a tank (64l tank I think)... All the car dealers claim how economical they are - an 800km trip was claimed on one tank before the fuel light came on...

So I was thinking lets list up what people get... To be beneficial I suggest the format below to allow easy comparison.

Your Country
Year
Engine variant (eg 1.8 GDi, 2.0 6 cyl 2.4 turbo)
Transmission - man or tippy
2WD or 4WD
Fuel used (eg 91/96/98)
Approx km/tank
Approx volume per fill
Calculated economy (either l/100km or km/l or mpg)

Anything elso you think might clarify - eg modifications, your driving style etc etc

It'll be interesting to see what the norm is...

Hi Guys

I too have a Lengnum 1.8 gdi gas guzzler, but found if driven manually it dont eat as much. Have found a web page of stockists of 98 octane in NZ http://www.palmy.net.nz/mr2dog/guides/petrol.html

Hi there.

Your Country: New Zealand
Year: 1997
Engine variant: 1.8 GDi
Transmission: Tiptronic
2WD/4WD: 4WD
Fuel used: 96 octane
Approx km/tank: avg 350 town / 450 country
Tires: 215x45x75r
Intake: Standard
Exhaust: Standard
Mods: Catalytic converter removed after 122,000kms (no real difference except breaths a little easier)


I also have the Legnum 1.8 GDI. Doing long trips I calculated that fuel consumption would vary from 10ishL/100KM through to 13ishL/100KM. No rhyme nor reason why the variation except perhaps petrol age and brand.

My car was missing like it was running out of gas. I put foot down, and car would splutter. Take foot off the gas and would run nice. Problem disappeared after a few minutes and had no problems until months later when it did it again. Went away again, and finally happened again but real bad. I only just made it to the garage without it konking out. Could only press microscopically on the gas pedal, barely moving, without it spluttering and stalling.

Turned out that the high-pressure fuel pump was screwed. $2000!!!! I am so glad I bought a 3 year warranty, as the excess was a mere $75!

Car still CHEWS the gas. I get about 350km's per tank around town. Going up hills or towing, this car cannot do. Very little difference in acceleration occurs from when foot is 1/4 pressed through to fully pressed. I wonder if driving with wooden block under the pedal would make it cheaper to run, seeing it makes no difference in power nailing the gas pedal.

Oh yeah, it runs far better when no passengers, and on cold nights.

Hey Grolscchie

10l/100km wouldn't be too bad for a 4WD atuo wagon (I had a T4 Primera auto - it could suck down a nasty 15l/100km when pushed hard, the best I ever got was 8l/100km.

If you know someone with a timing light (or better still a mechanic friend who would swap 1/2 hour of their time for a dozen beers) you should check you ignition timing. Not too sure what it should be on the legnum, many cars have a specification on a sticker on the bonnet (look at underside when you have bonnet up).

Often cars are "de-tuned" (ignition timing retarded) when imported from Japan to NZ so that they can run on 91 without pinking. My opinion is you are better off running 96 and getting better performance and mileage (not to mention reduced risk of engine damage). That outweighs the extra 5c/l in my experiences.

BTW the fuel pump problem seems to be a common one.

Your comment about cold nights suggests that it might be worth making some mods to get more cold air to your intake...

Hi Hoppy.

Thanks for the reply. Car has warranty with Donnithornes here in Chch, hence the replacement fuel pump (phew!!!), so no mods allowed until it expires, else it's voided.

Next service, I will get them to check plugs, o2 sensor and timing. I never use 91 octane, except for this NZ new '94 Galant SEI 2.0 SOHC I just bought today. It said 91 Octane inside the petrol flap, so filled it with 91. I wonder if 96 would be better though.

I was told to buy AvGas from near the speedway in a petrol can and put 4L of it in per tank full in the Legnum. Apparently AvGas is the goods, and even such a small amount does a great difference. Only, the exhaust smell is a giveaway. ;-)

Hey Grolschie,

The symptoms your car are showing, are almost identical to what I'm facing with mine at the moment aye ><

You were precisely correct about power nailing the accelerator - absolutely useless. Worse of all, when the accelerator is fully pressed, which the car reluctantly reacts to it a few seconds later, it makes this
unhealthy 'croaking' sound at the the rear of the car, it sounded as if the muff was about to fall off. (But still unsure exactly where the croaking is from unfortunately)

Anyone else suffers the same problem as I do? Car was jacked up and nothing seemed to have loosen'd. *bangs head on the wall*

I too, have a 3 year warranty, might get that fuel pump checked out.
Have you tried '96 octane?


Thanks for that Grolschie,


Will

'96 is good, but quality varies. I was using PowerPills with good success:
http://www.take-colostrum.co.nz/powerpills.html

I was told that putting foot down means little as the computer won't give it more gas than IT thinks is needed. I am not sure whether I believe that, and wonder if driving with foot hardly on the pedal results in more economy - as opposed to heavier foot with same performance.

Actually I should say that those pills worked SO good that first go, my fuel filter got blocked so that the car wouldn't run and it had to be thrown away. There must've been a heap of crap in the tank and fuel line.

To those whose GDI that sounds like a tractor at idle,

Including mine, it jerks as if I had hydraulics installed!
It starts to jolt violently when the rpm drops < 750.

Well, my guess is to tune it above that 750 rpm mark and the car
should be stable, of course, the car will drink a lil' bit more - totally contradict the concept of economical fuel consumption huh ><

Open for any other possible solutions.


Cheers guys,


Will

Hey Will, why not take it into a Mitsubishi Service Center? If you have one locally that is? Jerking sound like it's running on only a few cylinders at low revs.

My local MSC has two workshops, but only one will deal with GDI cars because it's specialized. My guess is that it needs to go on the computer to diagnose. Sounds like something is wrong in the GDI (whether a blockage or a sensor or something needs replacing). Tuning the idle is like sticking a bandaid on an infected festering gaping wound. Best to figure out why it's running so bad. Are you running high quality platinum sparkplugs?

Plugging into the computer should tell you a stack of things. Even old VP Holden Commodores have a stack of diagnostic info to be read by attaching to a pc.

Just wondering..... how much fuel does the air conditioning unit on these suck? Does it affect consumption by a huge amount or only about 10%?

Just wondering..... how much fuel does the air conditioning unit on these suck? Does it affect consumption by a huge amount or only about 10%?

Round town air conditioning will hurt - both in power and in fuel consumption, expecially if you run it on max fan/min temp.

On open road, if you set it to a comfortable temp (not minimum) and low fan speed and leave it running it should make bugger all difference to economy. I have had 3 cars with aircon and I have never noticed a hit in economy with aircon running on long trips. It is certainly more efficient than the drag caused by having windows open.

If your aircon is consistently costing you more than about 5-10% (that is about a loss of 1km/l) then something is seriously wrong... my bet is less than 5% would be normal - that will be hard to notice.

Hi Hoppy.

Next service, I will get them to check plugs, o2 sensor and timing.

A good move if you can afford the cost, they don't do that for free.

I never use 91 octane, except for this NZ new '94 Galant SEI 2.0 SOHC I just bought today. It said 91 Octane inside the petrol flap, so filled it with 91. I wonder if 96 would be better though.

On a NZ model you should be sweet on 91, they are set up for that. You could try 96, but the benefit would be most noticeable if you advanced the ignition timing by 1-2deg (don't got outside specification)


I was told to buy AvGas from near the speedway in a petrol can and put 4L of it in per tank full in the Legnum. Apparently AvGas is the goods, and even such a small amount does a great difference. Only, the exhaust smell is a giveaway. ;-)

Av Gas - that will scrw any catalytic converter for sure - not to sure how good it would be for some other components. IIRC it has lead in it. I suggest you get it running good before you try anything like that.

'96 is good, but quality varies. I was using PowerPills with good success:
http://www.take-colostrum.co.nz/powerpills.html

I was told that putting foot down means little as the computer won't give it more gas than IT thinks is needed. I am not sure whether I believe that, and wonder if driving with foot hardly on the pedal results in more economy - as opposed to heavier foot with same performance.

Not too sure exactly how Mitsi's work, but fuel injected cars computers generally have 2 modes.

Open loop & closed loop. I can never remember which one is which but the differences are:

Open loop: The computer determines fuel input by means of a preset "map". This is used during warm up, idle (usually) and under heavy acceleration. This means that if you put your foot down it WILL put in the amount of fuel specified for the throtle position.

Closed loop: The computer determines fuel input from afformentioned map BUT will adjust it based on the feedback from sensors, such as the 02 sensor in the exhaust that checks richness/leaness. This mode operates whenever you are cruising to minimise emissions and optimise economy. If any of the sensors are bung (especially the O2 sensor) - then kiss your economy goodbye.

A computer check should advise of any faults in these systems. (You can sometimes do this yourself if you can find out how to start the test mode. In some cars (Nissan) the results are displayed via "engine" light on dashboard flashing back a code)

Aircon is set at 17c, fan on 1/2. :-)

I didn't realise that fan speed inside car affects how much work the aircon unit does. I thought the aircon unit at the motor was either on or off.

High fan speed will mean that more air has to be cooled, therefore the compressor will have to run constantly to cool all that air. At lower fan speeds there is less air to cool so the compressors often cycle on and off, or in some cars reduce the amount of compression, therefore reducing the drain on the engine.

Once the car is cool try setting the temp to about 20 - 23 (or whatever is comfortable) and set the fan to 1 or 2, or if you have it try the auto fan speed. In my Nissan that will adjust the fan speed and the amount of cooling to keep the set temperature.

The fans (Radiator fan - needed to cool the aircon heat exchanger and the cabin blower fan) do add up to a fair bit of power on their own - this will mean your generator will be working harder to keep the battery charged. This too will be stealing power from your engine, but not as much as the compressor.

Thanks Hoppy for the infos. Car has no catalytic convertor. Removed it last year. Chews about 380km per tank around town at last test on 96RON. It's not an NZ model, it's a Jap import. I was told that they really need 100 Octane by the mechanic, one of the reasons they discontinue the GDI.

Hey there , this stuff does the trick , worked for me . give it a go .

http://www.idealcarparts.com/default.htm?page=12

We finally got 98 Octane gas in my town a week or so ago!!!! Car runs a little peppier now.

Hi Guys:

My car is also experiencing the same problems that yours are having.

mine is a 1996 gdi 1.8L with manual tranny. i have taken the car to three top auto electricians and the concensus is a DEFECTIVE GDI PUMP!!!

I could not source a new or used one for the 1996 models so he decided to do a conversion on a GDI PUMP from a 1998 model.

The car ran sweeeeeeet for one day but the pump burnt up 'cause a lubricating oil line to the pump was not re-connected.

Now i am wores off that i originally was as i appears that the pump was damage beyond repair and blah blah blah....

Can anyone post a drawing of the internals of the pump and how it works...i want to take a stab at fixing it myself.

i have to fix the problem befor i sell the car 'cause i wouldn't want my enemy to go through what i did.

Hi Guys:

My car is also experiencing the same problems that yours are having.

mine is a 1996 gdi 1.8L with manual tranny. i have taken the car to three top auto electricians and the concensus is a DEFECTIVE GDI PUMP!!!

I could not source a new or used one for the 1996 models so he decided to do a conversion on a GDI PUMP from a 1998 model.

The car ran sweeeeeeet for one day but the pump burnt up 'cause a lubricating oil line to the pump was not re-connected.

Now i am wores off that i originally was as i appears that the pump was damage beyond repair and blah blah blah....

Can anyone post a drawing of the internals of the pump and how it works...i want to take a stab at fixing it myself.

i have to fix the problem befor i sell the car 'cause i wouldn't want my enemy to go through what i did.

Ouch. I had both fuel pumps replaced in my car. The main one, the high pressure one cost NZ$2500 ($US$1750) fitted!!!! Just as well I bought a 3 year warranty.

its the injectors that cause the surge i beleive plus the throttle boody needs to be cleaned every 30000km or so as they do not clean themselves like a normal car would (YOU WILL NEVER GET RID OF THE SURGE THEY ARE A BAD DESIGNED MOTOR END OF STORY)

How does one clean the throttle body?

either spray carb clean into intake around the butterfly somewhere (through a Vacuum hose is the easiest )keep revs up while doing it or car will stall and if to much is sprayed in at once could do damage(small chance but just do small squirts at a time
or the better method but if you do nt know what you are doing dont do this one remove conmplete intake manifold and soak in some sort of cleaner and spray carb clean down intake ports to clean the backs of the valves leave to soak over night

both these methods will get rid of ticking when the engine idles and increase power and make car run smoother for about a month or three depending on which way you do it

Cheers Stu

oh, bugger, i think i got this thread because i wanted to know why the crummy Holden that replaced my BELOVED Diamante SuperSaloon (as a taxi in the 'Naki) makes Steenky Sulphur Smells when i try to make it go as fast as the Mitsi did (which it doesn't, despite being 7 years newer and 800cc bigger). Siiigh...

About the only thing i can think of is that it's on LPG, does anyone know if LPG is infested with Sulphur?

I have a crap Mitsubishi Legnum 1.8 add me to your list of disgruntled Mitsi owners, these cars are absolute rubbish, my fault for buying it I spose...here are the symptoms, A/ Very poor economy, haven't measured it, but have owned a V8 (350 chev) and it would be on par with that, except it has no where near the grunt. B/ Always feels like I'm towing a boat, a bloody big heavy boat. C/ It broke down today... and it has noisy lifters...

I'm having problems with my 1999 24 Viento GDI Legnum. Lately it has started to show idle problems when first started. Regardless of whether it is warm or cold, the engine hunts up and down revs and sometimes stalls. Problem goes away once the car is moving about.

The other problem is that is doesn't go into GDI mode any more. It used to. Adn you would notice the revs drop and the dash GDI light come on. Doesn't do it any more.

I have driven it 30,000k since buying it 2 years ago. It now has around 130,000k on the clock. It has been run on 91 octane fuel which I just found out is not a good idea :(

I am in New Zealand and apparently our fuel quality here is crappy. Too much sulphur and not enough octane. I assume the sulphur in the Exhaust Gas Recirculation system causes sooty carbon buildup in the intake manifold? Presumably this soot also fouls the engine sensors?

How does the ECU determine the right conditions for switching to GDI mode? What sensors could be faulty?

I took the intake pipe off the manifold and disconnected the airflow meter and sprayed a heap of Carb Cleaner into the manifold while the engine was running. I drove it afterwards and it seemed to start and idle better but I can't be sure.

While the intake pipe was off, I noticed that after the engine was switched off the Electronic Throttle was making a high pitched noise like the sound of a modem connecting to the internet. I investigated more and could see the throttle butterfly valve opening and closing before stopping a few seconds later. Why would the throttle be doing this if the engine is off?

The car drives fine in all other conditions, even though the fuel consumption seems pretty high compared to the weak output of the engine. Switching to higher octane fuel made a positive difference in power though.

What could the long term effects of running on low octane fuel be? Has this caused the engines GDI failure or is it the sulphur in the fuel?