High Idling RPM. What went wrong?

saurabhkum · 23rd October 2007, 17:52

This Sunday when I was driving from Mumbai to Pune on expressway in my Accent a strange thing happened. I was climbing ghat with around 1500 to 2000 RPM range when suddenly the truck infront of me changed lanes and due to which I had to put brakes on my car . As soon as I pressed the clutch ( after relasing the throttle) I saw the Engine RPM climbing up to 3000 mark, shocked to see that I thought my Accelrator cable got struck or something like that I tried putting the Accelrator pedal in the similar fashoin we used to change gears in older bikes. Though the pedal was back to it's normal position before I could do that which confirmed that the cable was not struck. Within 10 secounds the engine was back to it's normal idealing level ( below the 1000 mark). Confussed i parked the car at Lonavala opened the bonnet to see if anything could be figured out but evrything was normal. The engine was also not over heated. Also I had not pushed the Car beyond 100 km mark.I continued my Drive to pune and no problem. The car is 6 years old with just 27,000km on board. The petrol used was normal one with System G fuel additive in the required quantity. The car was used with normal quality petrol untill 26,500 km and I've started adding System G just 500 kms back. Can the petrol with additive cause this problem.
Experts please advice as I don't want to take chances in City traffic with this issue. I've come back to Mumbai now and on my way back also the same thing happened just once but this time the it happened for 5 seconds. Then 1 thing which came to my mind is that due to fuel additive the problem might have creeped in so I've reduced the quantity of fuel additive and till now car is working fine.Also I've also never experienced before in city driving.
Experts please help.

Zappo · 23rd October 2007, 18:25

Aah! I would have started this very same thread a couple of weeks back but just never managed to.

I experienced the exact situation sometimes back while returning from office in a diesel Indica. The car is otherwise in top condition and has no issues. But that day just as I came out of a turn at pretty high speed (for city) I saw something in front and released the accelerator. As I started braking I also threw the gear to neutral. To my amazement the car started revving away to glory.

I just braked it to a halt and even applied the hand brakes. And then sat bemused watching this crazy happening. The revs went up to 4500 rpm! For a diesel car thats something real crazy. I was wondering what to do when all of a sudden it started dropping on its own. And within a minute came back to the normal revs.

I waited another few moments. When things looked ok I gingerly put the car in gear and started moving with all the readiness to throw the shifter to neutral if shows another bout of happy-revving. But nothing of the sort happened. I came back driving with a lot trepidation.

Kept a watch on things for a few days but it never repeated itself again. I am clueless but then as it never ever happened I decided to let it go as a once-in-a-moon thing. I will think about it if it ever repeats itself.

sbasak · 23rd October 2007, 18:48

Not entirely sure, but heard this can happen if air flow sensor sends wrong information to ECU.

dkamath · 23rd October 2007, 18:50

do not own a car with an ECU, but a friend of mine is facing frequent problems with the ECU in his Santro. The reason being his house situated on a slope and he has to accelerate every time while driving the car out. The service center in turn told him that its the ECU that 'learns' the driving mode and adapts itself with the driving condition. The solution offered to him is to disconnect and reconnect the battery terminal.
The experiences with both of you seem to suggest a kind of a bug in this adaptive controls of the ECU. let's wait for further comments

anupmathur · 23rd October 2007, 19:10

Quote:

Originally Posted by Zappo

Aah! I would have started this very same thread a couple of weeks back but just never managed to.
I am clueless ...

Ian Paice had experienced similar behaviour in his car many many years ago. Deep Purple had even made an album about it, and called it 'Ghost In The Machine'.

Hope this helps!

spadival · 24th October 2007, 09:27

Quote:

Originally Posted by anupmathur

Ian Paice had experienced similar behaviour in his car many many years ago. Deep Purple had even made an album about it, and called it 'Ghost In The Machine'.

Hope this helps!

OT: Think you have posted in the wrong thread by mistake.. Should go here -> http://www.team-bhp.com/forum/shifti...al-impact.html

gbpscars · 24th October 2007, 09:41

Should this help?.....

http://www.team-bhp.com/forum/techni...tml#post561545

http://www.team-bhp.com/forum/techni...it-solved.html

most probably,... YES.

Quote:

Originally Posted by anupmathur

Ian Paice had experienced similar behaviour in his car many many years ago. Deep Purple had even made an album about it, and called it 'Ghost In The Machine'.

Hope this helps!

that was a good one LOL.

hvkumar · 24th October 2007, 09:48

I used to have this sort of problem with my Matiz sometimes, but that was because the accelerator cable was getting stuck and not retracting. Used to open the bonnet and release the cable. Lubricating the cable joint helped solve the problem. Maybe you should check this and change the cable assembly in case that is the problem.

patkim · 25th October 2007, 20:00

I have noticed similar problem with my Alto LXi.
It is more prominent when I bring vehicle to stop after slow reverse.
I discussed this during servicing… but no convincing response except that this could be due to MPFI engine or something like that.

23rd October 2007, 17:52	#1
saurabhkum BHPian Join Date: May 2007 Location: Mumbai Posts: 479 Thanked: 115 Times	High Idling RPM. What went wrong? This Sunday when I was driving from Mumbai to Pune on expressway in my Accent a strange thing happened. I was climbing ghat with around 1500 to 2000 RPM range when suddenly the truck infront of me changed lanes and due to which I had to put brakes on my car . As soon as I pressed the clutch ( after relasing the throttle) I saw the Engine RPM climbing up to 3000 mark, shocked to see that I thought my Accelrator cable got struck or something like that I tried putting the Accelrator pedal in the similar fashoin we used to change gears in older bikes. Though the pedal was back to it's normal position before I could do that which confirmed that the cable was not struck. Within 10 secounds the engine was back to it's normal idealing level ( below the 1000 mark). Confussed i parked the car at Lonavala opened the bonnet to see if anything could be figured out but evrything was normal. The engine was also not over heated. Also I had not pushed the Car beyond 100 km mark.I continued my Drive to pune and no problem. The car is 6 years old with just 27,000km on board. The petrol used was normal one with System G fuel additive in the required quantity. The car was used with normal quality petrol untill 26,500 km and I've started adding System G just 500 kms back. Can the petrol with additive cause this problem. Experts please advice as I don't want to take chances in City traffic with this issue. I've come back to Mumbai now and on my way back also the same thing happened just once but this time the it happened for 5 seconds. Then 1 thing which came to my mind is that due to fuel additive the problem might have creeped in so I've reduced the quantity of fuel additive and till now car is working fine.Also I've also never experienced before in city driving. Experts please help.
	() Thanks

23rd October 2007, 18:25	#2
Zappo Team-BHP Support Join Date: Oct 2005 Location: Hyderabad Posts: 5,908 Thanked: 2,746 Times	Aah! I would have started this very same thread a couple of weeks back but just never managed to. I experienced the exact situation sometimes back while returning from office in a diesel Indica. The car is otherwise in top condition and has no issues. But that day just as I came out of a turn at pretty high speed (for city) I saw something in front and released the accelerator. As I started braking I also threw the gear to neutral. To my amazement the car started revving away to glory. I just braked it to a halt and even applied the hand brakes. And then sat bemused watching this crazy happening. The revs went up to 4500 rpm! For a diesel car thats something real crazy. I was wondering what to do when all of a sudden it started dropping on its own. And within a minute came back to the normal revs. I waited another few moments. When things looked ok I gingerly put the car in gear and started moving with all the readiness to throw the shifter to neutral if shows another bout of happy-revving. But nothing of the sort happened. I came back driving with a lot trepidation. Kept a watch on things for a few days but it never repeated itself again. I am clueless but then as it never ever happened I decided to let it go as a once-in-a-moon thing. I will think about it if it ever repeats itself.
	() Thanks

23rd October 2007, 18:48	#3
sbasak BHPian Join Date: Nov 2005 Location: CCU-LTN Posts: 607 Thanked: 16 Times	Not entirely sure, but heard this can happen if air flow sensor sends wrong information to ECU.
	() Thanks

23rd October 2007, 18:50	#4
dkamath BHPian Join Date: May 2006 Location: BLR / MLR Posts: 579 Thanked: 162 Times	do not own a car with an ECU, but a friend of mine is facing frequent problems with the ECU in his Santro. The reason being his house situated on a slope and he has to accelerate every time while driving the car out. The service center in turn told him that its the ECU that 'learns' the driving mode and adapts itself with the driving condition. The solution offered to him is to disconnect and reconnect the battery terminal. The experiences with both of you seem to suggest a kind of a bug in this adaptive controls of the ECU. let's wait for further comments
	() Thanks

24th October 2007, 09:48	#8
hvkumar Senior - BHPian Join Date: Nov 2006 Location: Mumbai Posts: 7,368 Thanked: 3,467 Times	I used to have this sort of problem with my Matiz sometimes, but that was because the accelerator cable was getting stuck and not retracting. Used to open the bonnet and release the cable. Lubricating the cable joint helped solve the problem. Maybe you should check this and change the cable assembly in case that is the problem.
	() Thanks

25th October 2007, 20:00	#9
patkim Newbie Join Date: Sep 2007 Location: NA Posts: 17 Thanked: 0 Times	I have noticed similar problem with my Alto LXi. It is more prominent when I bring vehicle to stop after slow reverse. I discussed this during servicing… but no convincing response except that this could be due to MPFI engine or something like that.
	() Thanks