[dadu]

Most car equipped with an ECU/ EuroII compliant do have a knock sensor. Even my 1999 Santro has a knock sensor

Originally Posted by v1p3r

This is all assuming your car is equipped with a knock sensor. Which most Indian cars aren't.

[yzfrj]

I hope WagonR has one too, if it has mine is not working I guess.
Knocks like crazy.

I'll try the "resetting" thingy and see how it goes.

I'm just worried as the MAS guy just said, its not an ECU issue and its the radiator that is at fault that causes the engine to run hotter and hence it knocks. He also claims the air conditioner will be less efficient now.
To make matters complicated he also claims its safe to run it like this and we can replace it in the next routine service.

I'm still getting chilled by ac and FE is like 13kmpl with ac inside city,
but it knocks the socks off at anything more than half throttle in any gear.

[ssjr0498]

Hi,
I beleive, pre September 2002 OHC Vtec's did not have a knock sensor! I am not 100% sure though. Because if you fill in fuel which is not good, the vtec knocks like mad.

Cheers
Shrey

Originally Posted by dadu

Most car equipped with an ECU/ EuroII compliant do have a knock sensor. Even my 1999 Santro has a knock sensor

[dadu]

The primary purpose of a knock sensor is to adjust the timings on-the-fly to reduce the knocks. If the knocks continue, then it doesnt have one but if the knocks subside, then you can bet the sensor is working. Otherwise how does the engine know to reduce timings and it will knock throughout on bad fuel.

Originally Posted by ssjr0498

Hi,
I beleive, pre September 2002 OHC Vtec's did not have a knock sensor! I am not 100% sure though. Because if you fill in fuel which is not good, the vtec knocks like mad.

Cheers
Shrey

[Shan2nu]

The primary purpose of a knock sensor is to adjust the timings on-the-fly to reduce the knocks. If the knocks continue, then it doesnt have one but if the knocks subside, then you can bet the sensor is working. Otherwise how does the engine know to reduce timings and it will knock throughout on bad fuel.

I dunno about the later version of the OHC VTEC (post 2002) but my 2001 VTEC does knock if the fuel quality is bad. So i fill 91oct to be on the safer side.

Shan2nu

[dadu]

All car will knock at some point of time and thats when the Knock sensors will come into play. Its a corrective measure after the knock and not before.

Originally Posted by Shan2nu

I dunno about the later version of the OHC VTEC (post 2002) but my 2001 VTEC does knock if the fuel quality is bad. So i fill 91oct to be on the safer side.

Shan2nu

[Shan2nu]

All car will knock at some point of time and thats when the Knock sensors will come into play. Its a corrective measure after the knock and not before.

But i dont see the engine correcting itself. The car behaves the same way until i fill higher octane.

BTW, if my car does have a knock sensor, where is it usually located? I can check n tell you if it's there or not.

Found this image of a B series knock sensor - http://www.ff-squad.com/tech/sensors/ks.jpg

Shan2nu

[yzfrj]

Guys..! It worked

wow, I never expected the results would be this drastic.
It was knocking the socks off, now I cannot make it knock even if I floor it.
Hope it stays that way

Will be driving around during the weekend, will let you guys know if it improves and the FE too.
The MAS guy had almost got me convinced engine was overheating and a 4-5k radiator swap was unavoidable.

But as read in the thread, the cooling fan was not kicking in and same was mentioned elsewhere in the site. Actually I did disconnect and reconnect the Battery and the ECU before too as mentioned in the thread.

The dump thing I did was to put it back again real soon (like 5 mins)

Thanks you, Thank you, Thanks you...
All you wonderful people

"team-bhp" rocks man, seriously "Yo...!"

[Rehaan]

Originally Posted by v1p3r

...
I have an issue with this. It's well known that all civilian GPS apps have an inbuilt fudge factor. Added to which, India-located devices are accurate to 15m at best. Also, the average accuracy of a civilian GPS based device, is at best, 15m anyway. I still think a synchronised timer and laser based system is the most accurate. 15m is a hell of a lot in a 400m or 0-100 kmph scenario.

V1p3r,

I am no GPS expert, but i was doing some research on the VBOX a few weeks back and it has a resolution of about +/- 1 centimeter if i am not mistaken. (Dont forget that it uses GPS and inertial measurements combined). Absolute positioning is accurate to 3m. See below.

Also, as for the "civilian GPS" comments, i had heard similar things - but i think there are other workarounds (commonly available in civilian GPS devices) :

WAAS - accuracy better than 3m, 95% of the time (USA)
EGNOS - accuracy better than 2m, 99% of the time (Europe)

See this for WAAS : Garmin: What is WAAS? and google EGNOS y'self.

Originally Posted by yzfrj

...I'm just worried as the MAS guy just said, its not an ECU issue and its the radiator that is at fault that causes the engine to run hotter and hence it knocks. ...

Originally Posted by yzfrj

...wow, I never expected the results would be this drastic.
It was knocking the socks off, now I cannot make it knock even if I floor it....

Awesome! However, it could be that the ECU has adapted to cure an existing problem. It is possible that your engine is overheating and hence causing pre-detonation (knocking) - hows your temp guage looking? Do get your radiator checked out and see if there was any base for that diagnosis - or was it just the first thing that came into the mechanics head. Maybe even thermostat shut stuck or something like that?!

Originally Posted by ssjr0498

Hi,
I beleive, pre September 2002 OHC Vtec's did not have a knock sensor! I am not 100% sure though. Because if you fill in fuel which is not good, the vtec knocks like mad.

Hang on, did they not have a knock sensor??? Or were they just not mapped well enough for low quality fuel at low revs ? (ie even if the knock sensor was detecting knocks and the ECU was correcting for it it still wasnt within fixable limits).

Also, i seem to remember the pre-2002 vtec issue to be "jerking at low speeds" not "knocking" -- am i mistaken?

cya
R

[ASHISHPALLOD]

Hey all,
It works, it really works, it really really works.
Yesterday, after reading this thread, i had done resetting job as suggested by Dadu.
One month back, i had done servicing of Alto lxi and also changed battery to Ameron.
After that, i was feeling that pick up is reduced.
After exercising resetting job, immediately, pick up of car came to normal. I will post my comment about average on 21 st july as i will drive my car tomorrow for @ 300 km. Before resetting, average is 20 km/ lit on long run.
Thanks Dadu.

[yzfrj]

Originally Posted by Rehaan

hows your temp guage looking? Do get your radiator checked out and see if there was any base for that diagnosis - or was it just the first thing that came into the mechanics head. Maybe even thermostat shut stuck or something like that?!
R

Yes, Reehan I specifically asked him that could it be the problem of any other components in the system, he was blindly saying no and even refused to try flushing the cooling system. (Its just a waste of time saaar, we see this kind of problems all the time)

Temperature is as it was always showing (half way on the temp meter thingy)

It was reallllly bad during the peak of summer when temp was like 42-45. But this used to happened as soon as the engine warmed up (in say 2-3kms)

Anyways let me go for a drive (say 30-70kms) and see how it is.

[dadu]

Good to know its working for you guys, the ECU controls almost all aspects of engine in OBDII. Its a combination of fuel quality, oxygen and timings control.

The radiator fan is also controlled by ECU, btw.

[Shan2nu]

Hang on, did they not have a knock sensor??? Or were they just not mapped well enough for low quality fuel at low revs ? (ie even if the knock sensor was detecting knocks and the ECU was correcting for it it still wasnt within fixable limits).

Also, i seem to remember the pre-2002 vtec issue to be "jerking at low speeds" not "knocking" -- am i mistaken?

Just checked the engine. There is a black knob like thing with wires coming out of it, under the spark distributor. This might be the knock sensor.

Shan2nu

[Shan2nu]

How long does the ECU take to learn the limits of the engine? I just reset my ecu today, went for a drive, but see a vast "decrease" in throttle response and acc. Is this normal? Coz it feels like the car has lost 5-7bhp.

I redline my car almost everyday so maybe the maps my ECU had been using were performance oriented. Lets see what happens over the next few days.

Shan2nu

[rks]

Originally Posted by Shan2nu

How long does the ECU take to learn the limits of the engine? I just reset my ecu today, went for a drive, but see a vast "decrease" in throttle response and acc. Is this normal? Coz it feels like the car has lost 5-7bhp.

From your garage, I see that you have a freeflow exhaust (probably without catcon). And maybe you have cold air intake and performance air filter as well. After reset, the ECU is going to use the company settings, so that would account for the seeming loss of power. My guess is that you need to run a tankful or two to get back the old performance, but I am not sure about this. I hope you followed all the procedures that need to be gone through after ECU reset.