Problem with Vtec idling...varying RPM. EDIT : Solved! - Page 5 - Team-BHP

chetanhanda · 13th September 2007, 23:20

Quote:

Originally Posted by Mpower

Chetan, are you assuming that all cars have EGR. I'm not so sure that is true.
Also, blowby gases that are trapped into the crankase (PCV) and put into the intake downstream of the TB which suggests they shoudld go right into the engine rather than flow back and clog the TB.

The EGR s usually there in all new MPFI cars and GTO's car is a D15 vtec so definately it has one.

veyron1 · 14th September 2007, 02:13

Quote:

Originally Posted by chetanhanda

dude dont be so positive abt this..
Skoda = MAF
Cedia = MAF
Old indian ford escort = Alpha-n

Skoda- models sold in India= 1.9TDi & VRS (both boosted).
Cedia- Haven't checked the 4G94. Nice to know that it has an MAF.

Again, about alpha-n; okay, the Escort has an MAF. If it's running alpha-n, that's news to me as well. But I still do not get what alpha-n has to do here.

Quote:

Originally Posted by chetanhanda

dude can you please explain again as Im not able to get it...

All engines start in choke mode when cold. Mixture runs rich for the first 60-90 seconds. Haven't you seen the engines idling 2-300 RPM above normal when cold? This stabilizes once the engine is warm. It's common for all MPFI's from Maruti to Hyundai. And regarding the cars that I have seen which have had the idling problem, I also have to admit that the MAP sensors were also changed. Some under warranty.

Quote:

Originally Posted by chetanhanda

You wouldn't need a Idlecontrol valve's air supply when you are getting air via the main TB.

Yes, I'm aware of that. What I was implying was that I wasn't aware that the ECM cuts off return values once the TB moves off "0" position.

Quote:

atleast some here agrees

I wasn't disagreeing on anything. I was just trying to mix theory with the practical work that I've seen. I'm a novice, still at the bottom of the learning curve....

chetanhanda · 15th September 2007, 03:40

Quote:

Originally Posted by veyron1

All engines start in choke mode when cold. Mixture runs rich for the first 60-90 seconds.

dude who calls it choke mode ? anyways I got your point ..

Quote:

Originally Posted by veyron1

Haven't you seen the engines idling 2-300 RPM above normal when cold? This stabilizes once the engine is warm. It's common for all MPFI's from Maruti to Hyundai. And regarding the cars that I have seen which have had the idling problem, I also have to admit that the MAP sensors were also changed. Some under warranty.

veyron sir I know exactly what happens when engine is cold but thanks for the valuable inputs.
we usually say the ecu is in open loop, choke mode is a new term for me...

doomsday · 15th September 2007, 11:33

Quote:

Originally Posted by chetanhanda

The EGR s usually there in all new MPFI cars and GTO's car is a D15 vtec so definately it has one.

Are you referring to the engine code? If you are, AFAIK the engine code for the OHC VTEC in India is B15. The D15 series of Honda engines never made it to the Indian market.

chetanhanda · 15th September 2007, 22:27

Quote:

Originally Posted by doomsday

Are you referring to the engine code? If you are, AFAIK the engine code for the OHC VTEC in India is B15. The D15 series of Honda engines never made it to the Indian market.

D = d series
15,16,17 = cc i.e 1600,1700 or 1500 cc
thats why I call it D15 by mistake.
I know its an asian model but plz remember it is very similar to a USDM D series.
.. but I got ur point asian honda city is named differently
but its not a totally diff type of engine...

doomsday · 16th September 2007, 00:20

Quote:

Originally Posted by chetanhanda

D = d series
15,16,17 = cc i.e 1600,1700 or 1500 cc
thats why I call it D15 by mistake.
I know its an asian model but plz remember it is very similar to a USDM D series.
.. but I got ur point asian honda city is named differently
but its not a totally diff type of engine...

I understand the Honda Engine nomenclature somewhat. Guessed you might be referring to the same engine but D15 is the nomenclature in the USDM. Yeah, the B15 only came in the Asian market. Since you are usually very specific technically, while posting; I even thought it might be a typo.

GTO · 16th September 2007, 16:22

4 days up and the car is still revving over 7100 rpm. Last I checked, the limiter kicked in at 7500 rpm

doomsday · 16th September 2007, 19:47

Quote:

Originally Posted by GTO

4 days up and the car is still revving over 7100 rpm. Last I checked, the limiter kicked in at 7500 rpm

I say, take the car to the Honda authorized service and show them whats happening. I'm sure they won't have a clue about what is wrong...

You'll have a good time. You can pretend to be upset about the whole thing. These ASSs should get their due sometimes.

kaynmantis · 25th September 2007, 16:35

My car Ikon 1.6 has RPM problem too.

At stand-still, when I press & release throttle the RMP takes about 2 seconds to come back to idle. I take this to be normal.

On the move, say 60-70 kmph, I release throttle, press clutch & put gear to neutral, the RMP stays high. It remains high even after long period. In neutral with clutch fully depressed I start decreasing speed, the RPM gradually lowers. It comes back to idle when I am stand-still or almost.

Clutch seems okay as I can engage all gears effortlessly. Including reverse.
Driving is quiet unpleasant in this condition as I am unable to use engine braking efficiently.

Will appreciate any help.

im_srini · 25th September 2007, 17:44

This is regarding the question posed by QuickSilver, I too have pondered the same. Isn't positioning the O2 sensor in a single cylinder's exhaust pipe a rather inaccurate way to measure stoichiometric ratio ? Or is the difference trivial enough to ignore ?

pgsagar · 27th September 2007, 23:20

I saw this higher idling problem in my cousin's 3 day old Maruti SX4. As soon as the car is started the rpm shoots to 12-1300. After a few seconds it settles around 800. Now that's ok. It's not such a big problem. But what is very irritating is that even while driving the rpm keeps shooting every time you press clutch to change gears. It is very irritating in city driving because after changing gear when you release clutch the car just jerks forward as though it would hit the rear bumper of the car ahead. Any idea where the problem lies.

rdkarthik · 28th September 2007, 01:41

Few things that can help us all

1.Most cars with MAF also have a MAP sensor.

2. Idle Air Control still has a lot of work to do even when throttle goes from 0 to wherever. Thats where drivability comes in.

3. Rev limiter on almost all cars is based on time between reference signals ( cmp , ckp) and not on analog voltage

4. ECM resets cannot increase rev limit.

GTO · 28th September 2007, 14:40

Quote:

. As soon as the car is started the rpm shoots to 12-1300. After a few seconds it settles around 800.

Normal for any MPFi car when cold.

Shan2nu · 28th September 2007, 14:47

Quote:

4 days up and the car is still revving over 7100 rpm. Last I checked, the limiter kicked in at 7500 rpm

Same thing on my Vtec. Ever since the O2 sensor conked off, i've been able to revv past 7100. I've taken it to around 7400 without cutoff (didn't wanna go any higher).

But i generally shift at 6900-7000 so it's not that big a deal for me.

Shan2nu

GTO · 28th September 2007, 17:26

Quote:

Same thing on my Vtec. Ever since the O2 sensor conked off, i've been able to revv past 7100. I've taken it to around 7400 without cutoff (didn't wanna go any higher).

LOL! A third known example of this.

@ rdkarthik : How?

16th September 2007, 16:22	#67 (permalink)
GTO Team-BHP Support Join Date: Feb 2004 Location: Bombay Posts: 13,417 View My Garage	4 days up and the car is still revving over 7100 rpm. Last I checked, the limiter kicked in at 7500 rpm __________________ GTO Change the way you think, and watch the world change around you. Please don't PM for support. Use the Contact Form instead. Please read the NEW Team-BHP FAQ section for all your queries.

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25th September 2007, 16:35	#69 (permalink)
kaynmantis BHPian Join Date: Jun 2007 Location: Mumbai Posts: 73	My car Ikon 1.6 has RPM problem too. At stand-still, when I press & release throttle the RMP takes about 2 seconds to come back to idle. I take this to be normal. On the move, say 60-70 kmph, I release throttle, press clutch & put gear to neutral, the RMP stays high. It remains high even after long period. In neutral with clutch fully depressed I start decreasing speed, the RPM gradually lowers. It comes back to idle when I am stand-still or almost. Clutch seems okay as I can engage all gears effortlessly. Including reverse. Driving is quiet unpleasant in this condition as I am unable to use engine braking efficiently. Will appreciate any help.

25th September 2007, 17:44	#70 (permalink)
im_srini BHPian Join Date: Sep 2006 Location: Chennai Posts: 342 View My Garage	This is regarding the question posed by QuickSilver, I too have pondered the same. Isn't positioning the O2 sensor in a single cylinder's exhaust pipe a rather inaccurate way to measure stoichiometric ratio ? Or is the difference trivial enough to ignore ?

27th September 2007, 23:20	#71 (permalink)
pgsagar BHPian Join Date: Nov 2006 Location: Vizag Posts: 135 View My Garage	I saw this higher idling problem in my cousin's 3 day old Maruti SX4. As soon as the car is started the rpm shoots to 12-1300. After a few seconds it settles around 800. Now that's ok. It's not such a big problem. But what is very irritating is that even while driving the rpm keeps shooting every time you press clutch to change gears. It is very irritating in city driving because after changing gear when you release clutch the car just jerks forward as though it would hit the rear bumper of the car ahead. Any idea where the problem lies.

28th September 2007, 01:41	#72 (permalink)
rdkarthik BHPian Join Date: Sep 2005 Location: bangalore Posts: 198	Few things that can help us all 1.Most cars with MAF also have a MAP sensor. 2. Idle Air Control still has a lot of work to do even when throttle goes from 0 to wherever. Thats where drivability comes in. 3. Rev limiter on almost all cars is based on time between reference signals ( cmp , ckp) and not on analog voltage 4. ECM resets cannot increase rev limit.