[Born2Slow]

A week back my sx4 wont start because of week battery. I managed to push start it. As the problem persisted I removed the battery and saw that one of the cells was low on electrolyte so topped it up with distilled water and charged it using my inverter charger. After that the battery was fine but a new problem cropped up - the car wont idle.
Initially when the trouble started it used to stall when the clutch was depressed while driving but later on the problem became worse and it will not idle unless the throttle is slightly pressed. Reading through the sx4 shop manual it was mentioned that a throttle re-calibration has to be done by removing the battery for more than 20 mins and then after reconnecting the batteries keep the car in ignition for 5 seconds for the throttle body to reset itself. I carried out the procedure as per the manual but the problem resurfaced after about a couple of starts.It makes no difference whether the A/C is on or off. On starting the rpm initially goes to about 1200 and then slowly drops to 400 and stalls.I checked the battery voltage it is 13.7 volts (no load).I am able to start the car in the mornings without trouble, but the idle problem persists.
Now the car is at the authorized service, also 60,000 km service is due. What they are saying is it is because of the week battery. Somehow I have a problem with that because I use to start the car like 15 times in a short drive due to the idle problem and the battery never gave me a problem. Also how can a week battery cause idle problem as the alternator should be producing sufficient current to charge the battery at idle need be rather than depending on the battery. I asked them whether they tried it with another battery they say its working alright with another battery.
What do you think guys , do modern cars with ECM need the battery for stable voltage.
Thanks

[D.V.R]

Even my SX4 had a similar of low rpm idling and switching off.A through clean of the airfilter and the adjustment of the ecu rpm at M.A.S.S sorted it out.

[Born2Slow]

Thats what I am saying its unlikely that it is related to the battery. Also I forgot to mention that in the shop manual under the section "Improper engine Idle or engine fails to idle" there are about 18 points but week battery is not one of them. Any ways I told them that the battery can be replaced last if needed as they will be doing the 60,000 km service.
Thanks D.V.R

[vigsom]

Originally Posted by Born2Slow

after reconnecting the batteries keep the car in ignition for 5 seconds for the throttle body to reset itself. I carried out the procedure as per the manual but the problem resurfaced after about a couple of starts.What do you think guys , do modern cars with ECM need the battery for stable voltage.
Thanks

If your car is able to start,then the battery is not the issue.It could be a partially dirty throttle body

The sx4 works on drive by wire viz. the throttle butterfly is actuated electrically and not by a cable like say a old swift.

Just get the throttle body cleaned,and reset the TB(as mentioned in the sx4 shop manual) ; drive the car for a few kms for the ecu to get data and then things should be fine.

[sudev]

What is the procedure you followed for throttle body re-calibration?

I;d say it is more likely a ECM reset issue. This is a easy DIY procedure.

Just remove the earth terminal of battery for few (~5) minutes. Press bake paddle a few time with ignition switched on. Remove ignition keys. Now reconnect battery. Start the car and do not press accelerator. Let it idle for few minutes before you drive.

If this does not help the matters then get throttle body cleaned up and also clean up terminal connectors of the body with something like WMD40 spray.

[dhanushs]

Originally Posted by sudev

I;d say it is more likely a ECM reset issue. This is a easy DIY procedure.

Just remove the earth terminal of battery for few (~5) minutes. Press bake paddle a few time with ignition switched on. Remove ignition keys. Now reconnect battery. Start the car and do not press accelerator. Let it idle for few minutes before you drive.

Hey Sudev, why do you need to press the brake pedal for an ECU reset?. Could you please clarify?.

[mayankk]

Originally Posted by dhanushs

Hey Sudev, why do you need to press the brake pedal for an ECU reset?. Could you please clarify?.

i dont know about this situation, but usually when you have the battery disconnected for anything(i did for filter install), it is to drain away any residual electric current.

[sudev]

yep mayankk is right. Any residual current in capacitors is drained off when you press brakes or switch on lights.

[Born2Slow]

Thanks guys I had tried everything you have mentioned except cleaning the throttle body. But the problem refused to go. will update once I get the vehicle after service.

[Jaggu]

Try with a different battery, yes a weak battery can put load on the alternator but highly unlikely that it can cause a stall, but if the rpm was already borderline might cause this??

Throttle body and air mass sensor clean up, more probable reason.

[Born2Slow]

Got my car back yesterday. Its idling fine now. No clue what the problem was.Still running the old battery, as of now saved 4k,but not sure for how long.

[Jaggu]

Might have been a clogged air filter also

[miraauto]

HI,
If problem again comes with your car than pls do the reset procedure of throttle motor when you car coolant temperature is lowest. Means remove battery terminal at night and connect in morning and than follow the shop manual procedure. Reason for this is because in all MPFI cars RPM automatically goes near to 2000 when cold started for the first time in morning, this is because ECT(engine coolant temp sensor) send signal to car that its cold now so RPM increases. So at this point of time ECM reset the motor to maximum opening which will definately solve your problem.

I have solved this problem many times, the same way.

Also you not mentioned total km clocked of your car. Older SX4 had problem of exhaust valve cracking. Maruti head valve quality very poor in sx4. They are less hardened. This problem are more frequent when car runs on cng. For finding this you needs to check the compression off each cylinder with a good compression guage. If there is diffrence more than 1 kg between any two cylinders problem lies there for improper idle.

Pls check above things and let me know we will definately solve this.

[mayankk]

Originally Posted by miraauto

HI,
If problem again comes with your car than pls do the reset procedure of throttle motor when you car coolant temperature is lowest. Means remove battery terminal at night and connect in morning and than follow the shop manual procedure. Reason for this is because in all MPFI cars RPM automatically goes near to 2000 when cold started for the first time in morning, this is because ECT(engine coolant temp sensor) send signal to car that its cold now so RPM increases. So at this point of time ECM reset the motor to maximum opening which will definately solve your problem.

I have solved this problem many times, the same way.

Also you not mentioned total km clocked of your car. Older SX4 had problem of exhaust valve cracking. Maruti head valve quality very poor in sx4. They are less hardened. This problem are more frequent when car runs on cng. For finding this you needs to check the compression off each cylinder with a good compression guage. If there is diffrence more than 1 kg between any two cylinders problem lies there for improper idle.

Pls check above things and let me know we will definately solve this.

2000 rpm?
does your meter just jump to 2k for a milli second or so, or does it stay there for sometime?
If so, and youre saying youve resolved this many a times, by resetting the electronics(disconnecting battery)?
This seems like a prevention, less of a cure.

I think you are getting some warning signals/indications about getting your car checked, i think.

[dhanushs]

Originally Posted by miraauto

... this is because in all MPFI cars RPM automatically goes near to 2000 when cold started ...
... So at this point of time ECM reset the motor to maximum opening which will definately solve your problem...

There is a reason why the ECU takes the car to 2k rpms. Warming up the engine. I do not see why one would want to prevent warming up, and hence increase engine wear and tear. Or, am I missing something?

You should be concerned if the high idle persists, even when the engine is warm.