A thought about the Ecotek 'myth'

It won't do anything that drilling a tiny hole in the intake manifold wouildnt do. Same effect as screwing the idle mixture screw in a little. It runs weaker. So if its set up a touch rich it might help. If its set up a touch lean then it will be worse. At idle. At all other throttle openings it is completely irrelevant...

To speed up the idle as the motor is cold...

No. It controls the airflow to maintain the correct idle speed as programmed. Fitting an "ecotec" (or drilling a small hole in the intake) would then be cancelled out by the electronic idle speed control.

It does.t do anything that a leaky gasket that needs fixing wouldnt do. If it DOES lean the mixture it would be corrected the next time it went for a service by the mechanic...

If the ecotek has any effect on any car it is because the car is running to rich for optimum power or economy, and the ecotek leans it out. On any modern car which has closed-loop emissions control it would then do absolutely bugger all.

Cars which have IACV's tend to have closed-loop emmision systems, with a lambda probe in the exhaust, so the mixture isn't 'leaned-off' - it is automatically maintained at a predetermined air-fuel ratio. The purpose of the IACV is to give the ECU some method of stablising the idle rpm when ancilliaries (AC/electrical loads etc..) are on.

yup. Some people would argue that the effect is that the ecotek introduces additional turbulence into the manifold which supposedly helps fuel distribution and gives a more even burn. However, the air flow in most manifolds is very turbulent anyway, and the air volume allowed by the ecotek is tiny, especially at low manifold depression, so basically that's balls too.

What I mean is that if the Ecotek simply leans the mixture out a bit at idle - surely it's trying to do what an ICV does more effectively? Then, of course, if you've got an idle control valve, won't it automatically try to cancel anything out that the ecotek does?

I know, I know, there's been plenty of discussions about the Ecotek, I probably shouldn't have started another one. It's just one of those boring days at the office ;)

Chris.

No. The CORRECT mixture is err well correct! Leaner is wrong! But it will not lean it anyway, because the fueling increases to compensate for the added air on modern systems.

programmed.

They do not lean the mixture. They add air and the fuel system senses this and adds the extra fuel.

Then, of

Fair enough. I wasn't trying to say that all an ICV does is lean the mixture, just that they're both trying to do a similar thing, aren't they? That is, vary the air mix at idle - and that an ICV does a better job of getting it right than an Ecotek. Of course, you're gonna tell me that an Ecotek can *only* get it wrong, given the engine is set up correctly in the first place, I suppose - so whatever I'm talking about it somewhat moot. Here's another thought. My 305 suffers from an uneven idle. Most XU engined, L-Jetronic cars do, because they have a big spring-loaded flap for an air flow meter. At low revs, it keeps trying to shut, setting up a pulse in the intake system, making the idle go up and down. Now, would an Ecotek help even out the airflow in this scenario? Or should I just drill a little hole in the intake manifold? ;)

Chris.

I have an Ecotek Valve on my car, but it is an 1988 Escort carb. so I do get a little bit of benefit out of it. It does slightly improve the fuel consumption and acceleration but its not that noticeable. If you just want something to give a bit of roar under the bonnet then its worth getting one.

Nick

Yes you have missed the fact that the 'supplementary air device' or 'extra air valve' is to up the revs to about 1500rpm like the choke mechanism on a carb would crack the throttle plate open. This ensures a fast stable idle during warm up. I think they have gone back to cracking the throttle open a touch but now use a solenoid or solenoid controlled vacuum actuator.

The idle control valve does just what it says, controls the idle. It maintains a stable idle whatever the load variations produced by things like rear screen heaters and all the other electrical junk cars are now fitted with.

I get to have a third device, a FICD - Fast Idle Control Device. It opens to increase the revs when the air con is on.

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

Burgerman is right. A cold engine needs a lot more air than a hot one

- friction is higher, and you also want a faster idle speed because the combustion is a bit ropey when the engine is cold. Hence the extra air valve, controlled by the ECU, which opens when the engine is cold and closes when it is warm.

Nowadays a much more sophisticated system is used where the flow area of the "idle valve" is controlled closed-loop by the ECU in order to achieve the target idle speed. (In some cases the main throttle itself is jacked open by the ECU to adjust the idle air flow, but the effect is the same.) Crucially, in either case the air flow through the valve is included in the ECU's calculation of total air flow and so the fuel supplied to the engine is adjusted to suit - that is to say, the air flow through the idle valve does not alter the air:fuel ratio.

The Ecotek valve, of course, has no input from either engine speed or temperature so it is unlikely it can perform the same function as the idle valve. Additionally, its air is generally unmetered so it causes enleanment in a way that the idle valve does not.

I see Ecotek have abolished their Forum, by the way - I wonder if this is related to them promising in mid-May that the plan for their comprehensive test program would be posted there "in a few weeks"....

Tony

(replace "nospam" with "fuel" to reply)

No. The ICV controls the amount of air (not mix) at idle...

and that an ICV does a better job of

No!

No...

No you dont. If it does, then correcting your rich idle mixture would be a better solution.

No it does not!

If you just want

How sad...

The entire fuel-injection system, is continually cancelling out what the EcoTek does !

It *can't* improve your acceleration - it only operates when your foot is off the throttle !

The supplementary air valve uses air which has been metered, so is exactly like opening the throttle slightly. The Ecotek allows in unmetered air.

No it does not, it only operates when your foot is on the throttle to create an increase in the vacuum in the manifold. it draws in more air when more fuel is drawn into the cylinders, so creating more complete combustion and like they say "Bigger bang", hardly think 3 years of physics has taught me nothing. Their claims are not all completely false, but they only really have an effect on carb cars, fuel injection ones adjust the fuelling automatically so they are not needed.

Huh? You get maximum vacuum in the manifold when the throttle is closed, and that is when the Ecotek lets in most air. At greater throttle openings the inlet pressure is closer to atmospheric and the air-flow through the ecotek is lower, and is utterly insignificant compared to the air-flow allowed by the throttle plate.

If the car was running too rich, then at small throttle openings it might help by leaning the mixture, but the same effect would be achieved by having the fuelling corrected. If the fuelling is correct, then the extra air causes the engine to run too lean, reducing both power and economy.

???

When you open the throttle, the vacuum in the manifold decreases. It's at its maximum with a closed throttle, regardless of engine speed.

I'd question that. ;-)

It's many a year since carbs supplied a fixed mixture under all conditions.

Indeed, fuel injection systems with cats stay closer to a fixed ratio than most carb setups.

Obviously it has! When you stand on the pedal the inlet depression dissapears. Unfortunately this is the thing that "opens" the ecotec...

Errr yes they are!

but they only really

They havo only the effect of a leak on the inlet manifold...

Is that not the same thing? If it's varying the amount of air, it's varying the mix...?

OK I give up. I admit it, I'm all out of possible uses for that funny whirry thing. I woke up this morning and I felt much better, by the way - my idle curiosity (boom boom!) has been satisfied.

Chris.

No, because the ECU monitors the air/fuel mix and adjusts the fuel so that the mix, i.e. the air:fuel ratio, stays constant.

So you are right that the effect of the Ecotek on an ICV-equipped car is very similar to that of the ICV itself (or indeed any other small air- leak), but it doesn't affect the mix, because that is contantly corrected by the ECU.