LANCER 2003 4G15 GDI CVT Slow acceleration
 

Hi!
thank you for reading and trying to help.


Car is a Mitsubishi Lancer

MX-E Trim I believe

Yr 2003

from Japan

Engine

4G15 DOHC. GDI Invecs III CVT


http://topdents.com/ghts/lancer/car_...bishi_lancer.h

tm


Symptoms include :-
1.
Morning. car is cold. (outside temperature 15 - 25 C)
First ignition, sputters and dies.
Second ignition, catches, like misses a beat, struggles with

the choke. unsteady idle.
After like it warms up a bit, say 30 -50 seconds, idle

stabilizes.
If you accelerate right after ignition, nothing happens,

enven when you press the pedal completely
Like, after 3 - 4 seconds, then car moves slowly, slowy and

over the next 10 seconds, it starts to pick up speed.

2.
I feel even when engine is hot, no unsteady idle here, but

while car starts to move right away when pressing

accelerator pedal completely, I feel fisrt few

seconds,acceleration is slow.
that is from complete stop, accelerate is slow for first few

seconds. then voom.

Things we have done
Cleaned EGR (some carbon build up)

at one point a few weeks back, car would not even idle. just

die. and Idle air control valve was replaced with a second

hand one, not new (sometimes I feel maybe this may be the

problem)
Question :
Can a faulty IAC valve give slow acceleration first 3 -4

seconds on warm engine. or no acceleation at all for first

10 seconds approx on a cold engine?

Inspected exhaust manifold. no obstruction.
Catalyst gauze appears clear

Fuel pressure seems fine.
Fuel pump changed
Spark plugs checked / verified / changed.

Transmission fluid - Usual maintenance. recently changed.

problem from before changing. Change has not affected

behaviour

Throttle sensor seems to be working
Assembly that holds throttle senson and IAC etc on intake

manifold appears clean, no carbon, etc

MAP ( I don't think there is a MAF sensor here, so only map)

sensor was changed with another one from another car

working, and no change in behaviour is mime
same for ECU


Can someone please help me out.
May God reward you with better.
Thank you

email is

topdents@yahoo.co.uk

do the revs increase when you're trying to accelerate? that would indicate clutch slip.

could just be that you have a little engine and it's tied to a heavy gearbox.

in the oldentimes i'd have told you to stand on the accelrator before starting to disengage the fast cam on the carby... but it don't go like that anymore...
try cranking and starting while holding the pedal 1/4 down, when it catches/fires, hold the revs at 1500 for a few seconds.

Thank you for replying and advising.
Revs usually increase when accelerating, car picks up speed too. Just those few seconda (2 -3 ) where I feel the car is slow in reacting...
Re. little engine / heavy gearbox.. well, I have had the car for 10 years.. and the last 9 1/2 years, it has been a gem of a car to drive...

ah. So a new problem. Have you had the clutch replaced?

What i meant was, do the revs increase disproportianately to the vehicle speed?
Def sounds clutch issue at this stage...

Mitsubishi Lancer CS2 - 4G15 GDI CVT
 

Coming to a full stop at an intersection traffic light, the car works normally. But when the light changes to green and I try to accelerate the car moves at a snail's pace. The car engine does not rev even though the pedal is floored, after a few seconds the car kicks off on it's own and continues normally. This problem occurs maybe once a week and is not consistent. Already checked transmission, alternator.