Possible fuel problems on Lancer (only when it's hot)

R

Ralliart Mivec

New Member
(posted this on another forum, and haven't found a solution)

It’s my first time to this forum so I would like to say Hi first of all.

I’m currently having problems with a Mitsubishi Lancer CE Coupe 03 (not modified)

The problem has been going on for around a year now but has started getting worse, but only happens on very hot days like yesterdays 36deg.

The car will be travelling fine and all of a sudden have no power, pushing the accelerator will not increase the revs. Almost like the car isn’t getting enough fuel.

The problem started about 1 year ago and filling the petrol tank up from ¼ to full would normally fix the problem.
Yesterday it happened again, the car was ¼ full and filled up the car think that everything would be ok but no, the car started jerking again with no acceleration.

The car will not display any warning lights or problems other than losing all power, but the engine will stay on.
We have had it to a number of mechanics with no result; the injectors had been cleaned as we are only getting around 300km from one tank as well. Keeping in mind that this car is un-modified I feel that it’s very low. My highly modified 1.6l Mivec will get around that.

At this stage I’m thinking that it’s got something to with the fuel pump or maybe even pressure inside the tank.

The car is being sold in the next 3 months but would like to get the problem resolved before then.

Any information would be greatly appreciated.

Thanks
Ronny
 
have you tried o2 sensor? when you talk about spluttering and bad economy that pops to my mind.
 
is the tank venting correctly, has the tank been checked for 'suck' (vacuum inside the tank) as you have eluded to?
do you get a big whoosh of air running in when opening the filler?
 
tryg said:
is the tank venting correctly, has the tank been checked for 'suck' (vacuum inside the tank) as you have eluded to?
do you get a big whoosh of air running in when opening the filler?
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hmm very interesting.

To be honest I'm not too sure.

In the passed we though it was when the fuel level was too low, we filled up the car and it was fine again.

However last Saturday the wife called me up and said the car is doing it again.
Drove the car and it was stuffed again, filled it up with Petrol and all ok. However filling it up with petrol will actually vent the tank, and having a fuller tank will have less air I'm guessing.

However even after filling up the tank, 20min later on a 35deg day it happened again.

What do I check to see if the tank is venting ok.

Thanks
 
Royzie said:
have you tried o2 sensor? when you talk about spluttering and bad economy that pops to my mind.
Click to expand...

I've got a wiring diagram now and a ECU pin out diagram as well and will test the O2 Sensor with a Multimeter sometime this week.
 
does this model car have pre and post O2 sensors? could you change out some with a mate to see if that solves the issue?

maf sensors also cause spluttering too, I have seen this in motorcycles...

Good luck
 
Tryg might be onto something in regards to a low pressure building up in the tank.

One other thing, has the fuel filter been changed?

Also what fuel do you use?
 
also, check to see if you can hear rattling in your catalytic converter.. if it has collapsed/failed, it may be blocking your exhaust gasses.. that is another hesitation/power robbing issue with older cars/bikes....
 
tryg said:
does this model car have pre and post O2 sensors? could you change out some with a mate to see if that solves the issue?

maf sensors also cause spluttering too, I have seen this in motorcycles...

Good luck
Click to expand...

Yeah MAF can cause issues with fuel mixture and power (1.5Ls don't have one, but the 1.8L does). When my one in the CJ crapped itself I lost all power above 3000RPM and it would start spluttering. At idle it would surge, cut back and almost stall, surge...almost stall...surge....etc so it's not exactly what yours is doing although the 4B is a very different beast of motor to the 4G.

Also I think the CEs only have 1 O2 sensor before the cat. Newer cars only have the post cat ones for the newer and more strict emission control, serves no 'useful' purpose as far as the motor is concerned....
 
Ryan said:
Newer cars only have the post cat ones for the newer and more strict emission control, serves no 'useful' purpose as far as the motor is concerned....
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Oooh Ryan, a contentious point for sure!! Surely the closer to Lambda this sensor reports, the more median the fuel table... no sensor, a super-rich condition may ensue...

In fact, if I had a dollar for every bike I have fixed where the owner has disconnected the sensor somehow and complained of fouled plugs every week....hehe :lol:
 
tryg how would u fix the like air pressure sound coming out of ur petrol tank filler when u open the cap?
 
tryg said:
does this model car have pre and post O2 sensors? could you change out some with a mate to see if that solves the issue?

maf sensors also cause spluttering too, I have seen this in motorcycles...
Click to expand...

MAF sensor actually doesn't do that much sure it gives you some sort of petrol economy and a car that doesn't struggle to not stall on idle, but you can drive like normal without one.

To me it just sounds like really *poo* spark plugs, at no pint do you mention you have changed them.
 
Maybe MAF does little with older cars, but the fuel tabling is quite sensitive in newer cars and bikes, there is only a 15% window for change in most vehicles, some less...

Disconnect the MAF and a lot of cars splutter like crazy, my bikes stall... I think you're probably correct about the plugs, but modern day sensors are integral to correct function, saying otherwise is just settling for a pig of a car...
 
+1 to what Tryg said. When my MAF died the car struggled to idle, it lacked power when driving and soon as it hit over 3000RPM it spluttered that bad you had to back off. So for new cars they are an integral part of the feedback control loop for the ECU. As for the CE maybe it isn't as important....
 
so was the problem fixed ? i was thinking maybe a small crack in one of the vaccuum hoses letting air in the line after the sensor..
that is if the sensor is ok.. my sensor has been replaced - mine woudlnt even start properly when my sensor blew.
 
Fuel pump stuffed getting too hot from running with minimal fuel in the tank, filling the tank is allowing the pump to cool down. Other wise check plugs and coils, ce 1.8's suffer from failing coil packs due to heat. They will fail when hot with no warning same with the crank angle sensor. Have you had the trouble codes checked.? Perhaps take it to a good Mitsubishi dealership. Were are you located.?
 
Samwyz said:
tryg how would u fix the like air pressure sound coming out of ur petrol tank filler when u open the cap?
Click to expand...

Can you really fix this? I think it is normal for the air pressure to come out of the filler when u open the cap. Well, you could wait for 1 or 2 minute after turning off ur car at a petrol station before you open the cap to fill in petrol. Am I rite?
 
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