Smoke when cold and increased fuel consumption

[Guest]

Hi there fellow members,

I have been reading the forum a lot recently but haven't been able to find answer to my questions. My car is 2001 automat type S and it is a wagon. No mods, just bov and boost meter with turbo timer.

The first problem is quite annoying on mornings. It smokes from exhaust: like devil himself. It smokes when accelerating even more as you can imagine, it renders driving conditions behind me to be quite foggy. It decreases when engine and exhause is reaching its working temperature, I would say 1-2 minutes after the engine is at correct temperature it starts to behave normally (exhaust visual emmision).

The second problem is fuel consumption related. I drive highways in 95%, I drive at 110-130km/h, almost no speeding above, no unnecessary breaking, no overcoming ect, it is kind of driving that should give you fuel consumption at almost minimum. Well mine is quite dissapointing when compared to Your results, I have like 13-14l when I drive little bit faster it is going to be lot more like above 16l. Driving this slow way I can hardly achieve 450km on full tank (till it stops completely out of fuel, no worries I have carnister with gas in the trunk for these tests) I think 400 is an average. There i no mountains on my way, no big hills or whatsoever, just usual flat highway.

Recently I tested for ECU errors and it returned to me 64 but I just reconnected alternator terminal and after reset and driving a while it is gone, I do not know maybe just for now or it might be for good. Fuel I am using is premium unleaded shell vpower 99+ octane, never used another actually. Tires are 225/50/17 winter. I do not feel any drag resistances like stuck breakes or whatsoever. I haven't changed leads nor plugs recently (it is kind of fresh bought car).

Could you point me to the right direction or help me to find it myself at least.
Thanks in advance.

 

[Guest]

possible dead/dying EGO sensor,
a dirty air filter can also contribute to poor economy.

you don't have a pod filter do you?

most you can/will get out of a full take would be 500-520km mark,
(bradc will say otherwise but his car isn't normal and nor is he)

what colour is the smoke?
if its white its water,
if its blue/purple its oil,
if its black its petrol,

 

[Guest]

Thanks Gly,
Means that I have to use manual specified test procedure for oxygen sensor/s right? are there any Denso numbers for oxygen sensor known yet? I do not like to buy original since the price will kill my pockets.
Air intake filter this car has is a simple stock one or some equivalent part, haven't changed it yet. I can do so on the morning but I do not know if Galant EA5x 6A13 SOHC (N/A) filter will fit specifications- that is the only new piece of filter I have got at home. Besides Mitsubishi dealers here do not have either idea or tools to find me anything except for parts that suits EAxx models, well they have correct soft somewhere else but it is then easier faster and cheper to go thru internet order.
Well that will be nice if after repair/fixes I can reach 500km out of full tank. You see I am preparing this car to mount LPG alternatively to petrol and for this car, in its present condition it is not really a good idea to do so- mean without fixing the problem first.
The exaust smoke is not black, it is not purple either it might be light blue- it is kond of milky. hard to say while I can see it only in reverse mirror as at iddle there is no smoke, just wen driving with cold engine, to imagine the approximate volume of it: if the engine is cold and I speed from 40 to 50 km/h in about 2 seconds (not really a full throttle) it leaves a cloud behind me with volume of about 5-6 cubic meters and it spreads, when keeping speeding up at full throttle it keeps on smoking on the same way.
I have suspected cooling fluid to be a part of the troubles at the beginning, so changed it to new and after about 5000km its amount hasn't been changed so it does not dissapear from engine/cooler/reservour. Fluid has no contamination with oil, checked all 3 mentioned places already. Oil is also not contaminated with fluid.

 

[Guest]

sohc filter is the same,

mine does the same, i think the turbo seals are getting worn out, and untill there fully hot, a little oil/water is getting blow thru the exhaust system.

also no knowing where you are or you climate or where/how you park, there could be some moisture build up in the exhaust system

there is a aftermarket ego sensor number here on the forums somewhere, dunno where thought, have a search.

 

[Guest]

ok, will do so. I have ordered gaskets for exhaust already so I will take it out and have a look, airfilter will be changed as well. let you know after some longer trip next week or so- do not see the reason to bother without diriving constantly least than a full tank. after that I will have a look at the EGO sensor.
Thanks so far! Let you know.

 

[Sydo]

All cars 'smoke' when cold. Without seeing it for myself, it's hard to say if yours does so more than normal or not.
Condensation, running rich when on choke.. all normal.

Driving at 110-130 in these cars is never going to be good for fuel economy. At those speeds, the turbos would contantly be providing some level of boost. Drop back below 110 and save fuel.

 

[Hotwire]

^Agreed. When travelling from Adelaide-Melbourne recently (800km from my home to accommodation) In South Australia I was sitting on 120-125 and consumption was ~12L/100, when in victoria I sat on 105 the whole time and got down to 10.0L/100. That extra 20kph can make a difference!

 

[Guest]

OK, i will take that into account and post some 100km/h results, however my figures are above what you are writing. Regarding to smoke, it is not my first EC5x I have few to compare and none of 3 galants and 4 legnums does that as this one, small as usually amount of smoke yes but not clouds like that one. I remember when it arrived from Japan last winter it wasn't smoking that bad- afterall the car has been converted to LHD and it might be something what has happen in this progress.
By the way of EGO sensor replacement I could not find denso original part number when searching, found NGK- pretty expensive stuff. Lucky me- I have an original O2 sensors MD189008 in my garage and I didn' even realize that. Thanks to your forum found by ASA. From another mitsu (rear sensor) and used yes but low mil and it has worked well before dismounted.

 

[cyber_scriber]

Robert, I've seen a lot of tips regarding driving for economy. Many say that even driving at 90k/h vs 100k/hour gives substantially better economy.

In fact, I've read that the ideal speed for economy is around 75-80k/h (dependent on gearing, torque, power band etc of course).

Most of the record economy runs are done at an average speed well under 100k/hour.

 

[king_panther]

I've always been interested in the fuel economy arguments.

Something I've been curious about though is that yes you are saving 2L per 100kms by driving 20kms less an hour, but you're travelling less distance in that hour aren't you ? So how much more fuel is required to make that extra distance ?

So if you're doing 120km/h, you'll travel 120kms in that hour & use say 12l/100.

You slow down to 90km/h & you use say 10l/100. However after that same hour you've only travelled 90kms. So you have another 30kms to go, which is going to use more fuel.

At the end of the trip, just how much fuel has been saved ?

 

[Hotwire]

^ Time is irellevant to fuel economy. Bottom line is if its 120 kms from A to B, and you do it a rate of 12L/100km (120kph), you'll use 14.4L of fuel.

If you do it a a rate of 10L/100kms (90kph), you will use 12L of fuel, a 2.4L saving and still cover 120kms.

It will take you longer to get there at 90km/h, BUT you will still use less fuel

So you need to decide what is important to you - Time OR Money

 

[king_panther]

^ Time is irellevant to fuel economy. Bottom line is if its 120 kms from A to B, and you do it a rate of 12L/100km (120kph), you'll use 14.4L of fuel.

If you do it a a rate of 10L/100kms (90kph), you will use 12L of fuel, a 2.4L saving and still cover 120kms.

It will take you longer to get there at 90km/h, BUT you will still use less fuel

So you need to decide what is important to you - Time OR Money

Hmmmm... interesting. My bladder dictates how fast I have to drive :redface:

If I drive faster, the less pitstops I have to make, so the less stopping & starting.

I'd get crap fuel economy anyways as I'm mostly driving with a ton of gear in the back for my work.

 

[bradc]

Are you sure they are 225/55/17 tyres? That is 7.5% above stock, if you get 400km on the odo then you've actually done 430km.

I would suggest changing the tyres to 225/45/17 or 235/45/17 and to good summer tyres and then see what happens.

 

[Guest]

well Brad, I was so happy to run to the vehicle to check that, I found you are right these aren't 55 height just 50. re-edited original topic. But hey, that would have been a perfect explanation. so 45 height is the stock size, I will buy 45s after this winter is thru.