Honda Jazz 1.4 S.I V-Tec not working???help please

[guest3858]

Hi everbody i need Help with my Jazz tonight i chose to use the v.tec i was in 3 gear foot down rev up to 3500 nothing happend changed gear up to 4  again nearly 4000 rpm nothing happend after that put in 5 gear and i let revs back to normal d'oh!!!!!
What i am doing wrong?can somebody explain to me which gear and what rpm should the v.tec wake up?
My Jazz is 1.4 S.I  first reg September 2010.

[guest3469]

More right foot! You got to rev well above 4k to hear the vtec sing.  I love the sound of mine revving to 6k+. Peak torque is around the 3k mark but peak power is far higher. Have faith and dont be shy!

[Alan]

I think you are a bit confused about the workings of the V tec It only increases power at high revs on the Type R engine. On all the other engines it is designed to increase economy at lower throttle openings and therefore does not operate at the high end of the rev range.

The noise you hear at high revs is the sound of the engine and is nothing to do with V tec

VTEC ( Variable Valve Timing and Lift Electronic Control)) is a valvetrain system developed by Honda to improve the volumetric efficiency of a four-stroke engine

[chrisc]

Alan's reply is spot on.  The Jazz has been designed to be an economical motor and any extra performance due to valve timing changing will reduce this economy quickly.  If it were operating in normal mode all the time, you would have some small performance gain but the fuel consumption would not be nearly as good.

[guest3418]

And there are different vtec implementations for different uses. In the Jazz it is only de activation of a 4th valve. Normally the engine operates in 12v mode, when revving higher it is operating in 16v mode.
I believe this is the vtec-e implementation.

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[culzean]

The Jazz VTEC is the economy version,  12 / 16 valve,  but hey 100 bhp is not bad for a 1.3 litre engine.  You will see a power increase when the 4th valve starts to work and the engine can breath a bit easier,  but fuel consumption will increase.

[guest1232]

As they say, more motion requires more potion!

[guest2853]

I believe the jazz is always 16V. What changes is the profile of the cam. The Intelligent V tec system of our cars changes to a higher or lower (depends on the target of Honda) profile cam and only for intake valves.

The 8/16V behaviour is valid for the motorcycles; in particular the Honda VFR 800. I have driven the Vtec one and it is not very pleasant when at mid rpm accelerating the engine switches from 8 to 16 V especially if you are accelerating out of a bent.

[DV]

http://www.honda.co.nz/technology/

Choose your car and click on the Engine icon on the right.

[guest3418]

I believe the jazz is always 16V. What changes is the profile of the cam. The Intelligent V tec system of our cars changes to a higher or lower (depends on the target of Honda) profile cam and only for intake valves.

The 8/16V behaviour is valid for the motorcycles; in particular the Honda VFR 800. I have driven the Vtec one and it is not very pleasant when at mid rpm accelerating the engine switches from 8 to 16 V especially if you are accelerating out of a bent.

The Jazz uses/used a 12/16 valve VTEC configuration. There are multiple VTEC implementations in use, not all of them use a change in cam profile.

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[guest2853]

Are you sure this applies also to the 1.2 L B ivtec?

The 1.3 and 1.5 engines are for non EU markets.

[chrisc]

http://www.honda.co.nz/technology/

Choose your car and click on the Engine icon on the right.

That graphic is a very good explanation of how variable cam control works.

Yes, New Zealand models are the same as are sold in South Africa.  The owner's manual I have specifies differences between 1) Europe, 2) Southern Europe and 3) Australia/New Zealand/South Africa.

As far as I can tell from a quick read, it is mainly the servicing intervals and oil grades to be used.

[guest3418]

Are you sure this applies also to the 1.2 L B ivtec?

The 1.3 and 1.5 engines are for non EU markets.

The 1.3 and 1.4 are the same engines. For marketing purposes it is called a 1.4...

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[guest3469]

Ah, so its the change from 12v to 16v that is giving the extra oomph!  Makes me want to try a proper Type R now!

[guest2853]

So the engine has:
- variable valve lift while turning at 12 V
- variable valve lift while turning at 16 V
(of course only on the intake valves).

Is this correct?

Or is the lift of the valves constant and just the idling 12/16V that makes the difference?