4G18 IDLE PROBLEM

[HAYWIRE]

I HAVE A CS3 LANCER WITH A 4G18 ENGINE AND CVT TRANNY. THE BATTERY I GOT THE CAR WITH WAS GIVING ME A LAZY TUMBLE SO I PUT IN A 875 AMP BATTERY AND THAT IS WHERE MY TROUBLE STARTED.WHEN I STARTED THE CAR IT IDLED GOOD BUT WHEN I PUT IT IN DRIVE OR EVEN PUT ON THE A/C THE IDLE DROPPED SO LOW THAT THE CAR CUT OFF. A FRIEND TOLD ME TO DIS-CONNECT THE NEGATIVE TERMINAL AND LEAVE IT OFF FOR ABOUT 20 MINUTES TO RESET THE COMPUTER AND I DID,BUY THE PROBLEM IS STILL THERE...IM SURE THERE IS A PROPER WAY TO DO THIS AND THAT THERE IS A TUNER WHO COULD HELP ME. SO PLEASE HELP ME SOMEBODY

[Kronik]

try leaving the terminal off overnight to be sure, what you are doing is resetting the ecu

and when you reconnect the terminal, start the car and let it idle for 15 mins for the ecu to store the new settings

[JUS4SHO]

i dont think re-setting the ECU will help, and i am most sure that switching the battery is not related, haywire give a little more details to the problem like when when , if the tach fluctuates etc

[turbo_beast369]

read d owner's manual for d car. There is a re-setting process shown in the book. That happens when u change batteries.

[Mitsu power]

^^ got the same problem with my cs3 4g18 manual .. DM say its the step up sensor gone thats the guy by the TB where the coolant runs back into the TB .. they also say that this sensor dont go just like that and that its a faulty in the ecu that is to blame. so changing the sensor will not help and that you will have to change the ecu and sensor sensor is $400.00 tt i think cant remeber that one too good but remeber the ecu one $6000 tt lol remeber that good ....lol so I leave the bugger how it is and turn up the idle a bit via the idle screw by the butter fly spring where the trottle cable is connected so it wouldn't cut off ..not the screw in trottle body .. I mess with that in trying to patch my problem and the engine start doing all sorts of crazy things ..( adjust it when the engine is hot ,if you do it when it is cold it will over idle when hot ..

[JUS4SHO]

step up sensor?

you mean the idle speed contorl valve / motor is so its a very commy problem with all mitsu's that these ISC fail.. for the cs3a the p/n is MD619857

[Mitsu power]

^^ yup

[QG]

step up sensor?

you mean the idle speed contorl valve / motor is so its a very commy problem with all mitsu's that these ISC fail.. for the cs3a the p/n is MD619857

This is a valve control problem self...I get this same problem too . It's very annoying as well.

[mini me AWD]

this seems to be an issue with the 4g18- ive had problems with mine for months now- seemed to help with a new battery- but every so often- i get that idle drop- diamond motors i think wanted soemthing like $1000 plus for the idle up sensor- replace it- or bring it in yourself

[QG]

Waw..so much . DM does really play the fool yes.

[Around]

my gf cs3a 4g18 lancer start giving some probs, that seem to resemble this "idle speed contorl "

i recently changed the oils- Castrol synthec, mitsu sp3
then about 2 days after the vehicle started cutting off at low rpm's/standstill.
diagnostic @ Automotive component says everything is fine, but the mech thinks its low fuel pressure, new pump ($401-500 @ various dealers)

I dont think its the fuel pump tho cause after check up the car worked fine for 4 days with trouble free but Friday afternoon car wasnt starting. Had to real mash gas repeatedly bout a 100 times while tumbling engine to start and rev up alot then car stayed on like normal

Instead of fuel pump could D problem be
Residue in fuel line/tank, rust
clogged fuel filter
Idle Control (as mentioned)
Fuel Regulator (faulty/leaking to return hose)

Car started & drove fine this morning

juterams arima say dey have internal pump for 250 what goin on with these prices boy? geeeez

Opinons (HELP) welcome

[Around]

bump

[QG]

bump

[JUS4SHO]

around what meathod did the mechanic use to isolate that the pump if faulty

[Lancer01]

.WHEN I STARTED THE CAR IT IDLED GOOD BUT WHEN I PUT IT IN DRIVE OR EVEN PUT ON THE A/C THE IDLE DROPPED SO LOW THAT THE CAR CUT OFF. [/size]

I had the same problem with my car. I took it to a Top mechanic and he fixed the problem in like 10 seconds with a flat head screwdriver. If the problem still exixt, let me know

[JUS4SHO]

^^^^^
THAT IS NOT THE FIX AND WILL DESTROY YOUR ECU......ITS GOOD FOR A TEMP. FIX

[P3UNG]

having idle problems with my CS3A 4G18....it refuses to idle below the 1000rpm for more than 2 days...i've tried the flat head trick but its back up there at 1100rpms suckin my tank dry...i go thru a full tank (premium) in about 4 days....trincity to woodbrook..

i dont think its the idle speed control valve mentioned above..the car is 3 wks old (well i've had it from the dealer for 3 wks)

???

[venum]

^^^then carry it back and let them fix it under warranty

[anthonyanthony]

haywire, how long you own this car.
since you have it has an maintiance been done on it like replacing plugs, air filter,
using a gas treatment at an oil change etc. Is the check engine light coming on?

Get the vehicle scanned to see if any sensor etc. is going bad.

from reading the service manual , this car does not have an in line fuel filter that
can be changed. According to the manual the filter is built into the fuel pump or as
the manual call it the fuel pump module. This is in the gas tank, the manual does
not mention about changing/replacing/ cleaning this filter but if you have a good mechanic he should pull out the pump module and possible try to clean this filter.
also check to see if any residue in tank and lines and correct this

If this does not work according to the service manual , the idle is controlled by
a stepper motor called ISC motor located at the bottom of the throttle body.
Mechanic could take out this and see if ISC valve and respective ports needs
cleaning.

The electrical connection at this motor could also be checked to see if it is connected, corroded etc and not loose. In my 98 lancer this dropped out and was hanging for weeks but car did not give no idle problems!! Only noticed this when i was washing engine bay.

the screw driver fix is just temporary and not correct. (lancer01)

The throttle body has 3 adjustments, one to adjust slack on cable( via 2 screws and a plate), one to adjust opening of throttle plate and the next is to adjust air bypass for idle (this screw is covered by a black cap). Usually these should not be adjusted unless throttle body is serviced/ scrapped etc.

As i asked how old is the car, if the car has some age/ mileage these things can be an issue

If problem still their then get someone who services these cars, must have people like these on this forum or who can tell you where to go but leave DM as a last resort.

Wish you luck in sorting out this and hope you do not have to spend alot of money,
but keep us posted as to what is going on.

[P3UNG]

^^^then carry it back and let them fix it under warranty

venum so i carry it in today after i adjust the airflow with a flat head this morning...they tell me it wukkin normal...(didnt tell them i interfere with it).

i ask the guy if i have a problem again what do they do to fix...he say that they use the flat head method...i was like hmmm ok! wouldnt that affect the ECU...he say nah man...dat is how we do it.

what say you guys?

[JUS4SHO]

ok let me shead some light here that bottom of the trottle body where the isc is when you buy the isc it comes with that section as well ; now inside the trottle body just below the isc there is a small port with a thermostat this is feed with water fom the engine and adjust idle up or down depending on engine temp. so what i realised was it was not my isc that was bad it was this thermostat that failed... but i chaged the entire thing since i already bought it

actual pic of the genuine isc servo now thoes lines you seeing there are for the water NOT fuel

[anthonyanthony]

P3UNG , this is a new car , right, what D hell going on with DM?
sounds like OJT working there.

[P3UNG]

P3UNG , this is a new car , right, what D hell going on with DM?
sounds like OJT working there.

LOL!!! yeah man..its a brand new car...she'll be a month come the 29th..already did first service at 1000 km

[Pirate]

same thing happened to me and i had to change my Idle motor (stepper motor)...its been about 7 mths so far and no problems....

[anthonyanthony]

JUS4SHO what you are saying is that besides the engine thermostat there is another thermostat inside this unit controlling the motor besides the CPU?
If this is so you may be onto something.

I will consult the manual again but from memory the manual just shows how to check the motor using a meter to measure resistance at the various terminals and also applying a 5V power on terminals and feel for motor movement.

It did not mention about a thermostat in this area or about testing it.

By the way is the stepper motor or thermostat sold separatly or must it be bought as a complete unit like you did?

Also after install do you have to do adjustments to get idle speed or just install and computer will relearn?

What was the cost of this unit , was it cought at DM?

[venum]

good show guys

all good explanations

now we know why there are water lines going to teh TB

hmmm... didn't some men on the forums disconnect them

as for teh flat head adjustment

on my CK2 lancer the idles sometimes just dropped

not intermittently like teh CS3

this happened about 3 times in 6 years

but just dropped about 200rpm below norm idle (800 rpm)

teh flat head adjustment worked

[P3UNG]

no comment on the comment...?

[boost11]

P3UNG, i had tha same problem with my CS3..i carry it back in DM..car ent even make 1000km..the head technician tell me thaz normal and the rpms are supposed to drop off like that suddenly..he clean out the throttle body and even drive with me in the car and still said it was normal.. i find it rel annoyin so i will bring up the issue with dem again when i go bak for servicin

[P3UNG]

seen! ...they have other threads with idling issues, so doh touch nuttin...and carry it let them fix n repair.

injectors may need cleanin too..but let DM take care of it...i does carry back my car for most anything even to jus check suspension or to align, even had them do over my tint cause i didnt like the original tint job, still dont like it but i get them to darken the side windows

and i talkin in between service appts...any given day i talkin bout.

[boost11]

u get dem to tint over the whole car??? lol dey do rel rubbish the first time or wa?