Car shuts off (low RPM on Idling) after change in battery

[hdaackda]

AoA,

My Lancer 1.3GLX was running very smooth, until today I installed a new battery ! (no tracker).

After the battery, my RPM is suddenly low, the car shuts on if I brake or slow down, on CNG and on Petrol. What could be the problem? How can I rectify it?

Like old carburetor cars, do I need to increase the 'race'? ya kuch aur??

pls help. cant drive it like this. especially in the rain!!

[VCheng]

What year is your Lancer? Carb or EFi? How many miles on it?

[syncview]

during the installation of the battery, did they happen to pinch or maybe put the battery on a vacuum line?

[hdaackda]

@Vcheng: car is 2005 Lancer GLX 1.3L, EFi. 68,000 km

@syncview: pinch? vacuum line?

they just unscrewed the terminals, took the old one out and put the new one in.

btw, i am also selling this car IF i get any good offers.. nt desperate though.. chck link below (giving wrong name as HELP ME. lolz.. it shul be lancer)

https://www.pakwheels.com/used-cars/2005-Mitsubishi-Lancer-for-sale-in-Karachi-97704

P.S. also changed the oil, oil filter etc (caltex havoline.. the expensive one..) but i dont think that could be the reason?

[khahsan]

your ecu is reset bro, just get it computerized tunned again.
the problem will be solved.

[VCheng]

your ecu is reset bro, just get it computerized tunned again.
the problem will be solved.

This is correct. The fuel trim information has been lost when the battery was changed, and will be re-learned over 50 start-stop complete drive cycles. If you can wait that long, this problem should go away.

If it doesn't, you have another concurrent problem, like a blocked or malfunctioning IAC circuit.

[hdaackda]

thnkx vcheng. i can already noticing it improving!! i hope tuning kay liyay faltoo paisay mazeed kharch na kerna parain.. cause it was running VERY SMOOTH previously.
these electronic cars are -----. gosh

if it doesnt get alrite, will go for tuning then...

btw, i also had the car serviced (and engine washed, but with all electrnic parts covered in plastic bag). dont think tht did anything either

[pistonhead]

the ECU gets reset, i experienced it with my City. The RPM was going everywhere during idle, but in a few days, everything was back to normal. I guess its a good idea to not get the previous battery disconnected, and have the battery changed while the car is already running. That way the ECU would not get reset...

[VCheng]

thnkx vcheng. i can already noticing it improving!! i hope tuning kay liyay faltoo paisay mazeed kharch na kerna parain.. cause it was running VERY SMOOTH previously.
these electronic cars are -----. gosh

if it doesnt get alrite, will go for tuning then...

btw, i also had the car serviced (and engine washed, but with all electrnic parts covered in plastic bag). dont think tht did anything either

the ECU gets reset, i experienced it with my City. The RPM was going everywhere during idle, but in a few days, everything was back to normal. I guess its a good idea to not get the previous battery disconnected, and have the battery changed while the car is already running. That way the ECU would not get reset...

A better trick is to connect a 9V dry battery cell IN CORRECT POLARITY to the cigarette lighter outlet BEFORE disconnecting the battery.

That will supply enough power to retain the ECU settings for a short time while the battery is changed.

However, the new battery must be charged before being installed.

NEVER have the battery changed while the car is already running.

[hdaackda]

@vcheng: the reason for last comment? my battery wala said if ur car has tracker, then keep the car started and i'll change.. but i said no tracker!

dad uses the car and ts giving him trouble, so i'll take it for tuning on saturday to dewan motors.. dont knw how much they'll charge..

otherwise, anyone else knows a good person in karachi? and reasonable rates?

[VCheng]

@vcheng: the reason for last comment? my battery wala said if ur car has tracker, then keep the car started and i'll change.. but i said no tracker!

Disconnecting a car battery while the car is running has the potential to damage several critical electronic components.

[hdaackda]

btw, the car is running fine now!! didn't do anything! thanks a lot everyone!!

[VCheng]

btw, the car is running fine now!! didn't do anything! thanks a lot everyone!!

That's great!

[Xulfiqar]

the way I swap mercedes benz batteries is - by hooking a battery to the front (engine bay) positive lug and a negative point - then swap the battery out from the back. doesnt lose any memory.

You can achieve this by hooking a small car battery to any live thick 12V line (alternator lug or self starter lug or even the battery positive terminal - after first loosening it) and connecting its negative to the engine block or ground strap - then replace the main battery

[khahsan]

i prefer my car's ecu to be reset after every 06 months. it feels a new life after i do that..
any input, VCHENG?

[Bilaltq]

i prefer my car's ecu to be reset after every 06 months. it feels a new life after i do that..
any input, VCHENG?

That's a bit like saying, "I like to reset my clock every 30 days."

[hdaackda]

thnkx xulfiqr n vcheng.
khahsan: dont see any benefit frm tht sir

[VCheng]

i prefer my car's ecu to be reset after every 06 months. it feels a new life after i do that..
any input, VCHENG?

It's your car, and your preference. It sounds like your mind is already made up. I have to respect that. What input do you need?

[khahsan]

It's your car, and your preference. It sounds like your mind is already made up. I have to respect that. What input do you need?

i mean does resetting an ECU really helps in getting good MPG or some thing like efficiency in any manner....

[VCheng]

i mean does resetting an ECU really helps in getting good MPG or some thing like efficiency in any manner....

The short anwser is no.

Over time, the ECU learns fuel trim parameters that are lost when it is reset, and that usually causes minor dirveability issues until everything is re-learned.