ECO Mod: Howto reduce level of enrichment when cold

[flatbroke]

Looking at calculations above IMHO it is just easier to block radiator.

Just curious how that blocked a/c condenser and blocked trans cooler on the cvt models is going to work out?

[uheym]

Ironically, US market Mirages have an open recall to correct this very thing.

Anyone how knows if any European Space star had any recalls? I don't know any of them, so I'm just curious about if there where some.

[Teasmade]

Anyone how knows if any European Space star had any recalls? I don't know any of them, so I'm just curious about if there where some.

Certainly I've not heard anything in the UK, but then it may be one of those things that's subject to a TSB (Technical Service Bulletin) rather than a recall; I.E. When you bring your car in to a main dealer for service, they'll reflash the ECU on the quiet. Certainly that's what happened with a couple of things on my old i10 - It went in for an exhaust repair under warranty (yes, really!) and they replaced the headlamp adjustment switch (which was a common fault and subject to an updated part) as well.

We'll see in a week or two; I've got to book my Mirage in as there's a recall on some of the crash sensors; I got a letter through the post the other day. When I take it in I'll see if they're aware of any such campaign over here.

[cyclopathic]

Just curious how that blocked a/c condenser and blocked trans cooler on the cvt models is going to work out?

I would suggest to get OBDII reader, Torque Pro and monitor it. I have done that on Prius and the inverter and MGs stayed cool as long as the temps were below 70s. If you need to use A/C, don't bother it is too warm and it will not save you much on MPG.

[foama]

That, a engine heater, and this sensor circuit mod. Who will be the first?

Keep in mind that the value of R3 can be adjusted for different results. I think foama selected a value that produces mild changes without throwing off the operating temperature readings too much. I think his set up is rather clever. He could have gone with a more aggressive value.

I developed the chart to start that question off - what if we changed R3? Also, what exactly are the real world results of testing the entire setup, rather than guess at it? Put the sensors in a pot of boiling water and measure away.

Thanks Eggman, your calculation table is on par with mine.
Of course you could change the value of the series resistor. As you said, the mod as described is very cautiously dimensioned. As shown in the table the difference becomes close to nill when the engine aproaches operating temperature.
In my daughter's 1998 FIAT 900cc Seicento, R3 is 1700 Ohms, and the sensors are electrically identical, and no problems there either.

Btw: The lower part of the radiator-intake of my 1.0L Space Star is mostly blocked, with about one third left open. In addition, the bottom of the motor compartment has a cover on it. (see other thread)
Never had any heat problems, and can't remember when the fan came on last. Don't have a block heater.

[foama]

UPDATE:

Tried different values for the series resistor in my 1.0L Mirage, and this is what happens:

At 2.500 Ohms everything is fine.

2000 Ohms also works well.

1750 Ohms or less is no good, because the radiator fan will come on too early during warm-up with the radiator still being cool and the thermostat closed. Remember, this car has only one single temperature sensor for everything!

To sum it up:

1) any value between about 2500 and 2000 Ohms is fine.

2) This mod goes much further than the reprogramming of the ECU (USA recall) for enrichment reduction.

3) My car is a 1.0L without(!) EGR valve. Yes, the 1.0L engine without AS&G is sold in Europe without EGR, but the 1.0L with AS&G does have EGR.

I think using valve-overlap is maybe how they keep NOX down at testing-relevant revs and load levels, unless they VW their way out to get better figures...

[Eggman]

Foama, thanks for the update.

I've wondered how your mounting location for the second sensor impacts this modification. It would be nice if it too could be immersed in coolant.

[Eggman]

I just thought of one more thing - what about the intake air temperature sensor? Wouldn't that also affect this?

[foama]

Foama, thanks for the update.

I've wondered how your mounting location for the second sensor impacts this modification. It would be nice if it too could be immersed in coolant.

Since I see no feasable way to immerse the additional sensor in coolant, it was mounted as in the picture, being directly on the cylinder head. That is where most heat is generated, and where it gets warm first. The temperature there is just about the same as the coolant within the same head it is attached to.


The air intake temp sensor does a similar job, but most of that input affects ignition timing.

[gone.a]

Wonder how much fuel this actually saves. My car goes into closed loop literally in less than a minute after cold start and well before the coolant gets anywhere near up to temp. The o2 sensors warm up very fast and when in closed loop you are running at stoich. So you are only saving a small portion of fuel for a small portion of time.