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Old 06-18-2011, 02:17 PM   #46 (permalink)
beer
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This is an interesting topic, I also have a lean-burn honda.
It's not the same engine as they use in the States, I'm from the Netherlands so I have a europian modell with a D15Z6 lean-burn engine.

I'm also traying to figure out, which sensor's and which readings are necessary to engage lean-burn.

-TPS signal 20% till 32% load.
-IAT above 5*Celcius
-ECT (coolend temp sensor) temp??? (Think above the warm-up mode from de IAC)
-Gear sensor???? (if there is such a thing in ower car) in 1st or 2nd gear even in the right rev and load range LB doesn't activate.
-RPM sensor, till 3000rpm but as stated above to low rpm disangages LB to but I think its lower than 2400rpm about 1750rpm
-RPM fluctuation sensor (located near the crank shaft), (instead of a wideband lambda sensor used in the d15z1).

-Probably MAP sensor
-There is no knock sensor in the d15z6
-Don't know about a Cat temp sensor, looked for one but couldn't find it.


To accomplish sustainable lean-burn, there has the be some sort of temprature control.
This is done throught the use of EGR.
The EGR exhaust fumes in de d-series honda come directly thought a hole in the exhaust port of the (thought) 1st cilinder.
This is the reason why the block warms up and the catalitic converter cools down.
I know that alot off lambda sensors need heat, and have internal heat coils.
That maybe a reason why its deactivates lean-burn, to warm up the lambda sensor.

What i found remarkeble is that after accelerating, thus being out of LB, you don't enter LB very fast, but you can trigger it by giving it a short hit bit of extra load!?! and then lift of the throttle again.

Solution?:
I heard of slowing/altering the TPS sensor, I do think it helps to stay in lean burn but also delays fuel shut-off while decelerating and maybe dangerous for emerencies.

Has I wrote in the tread below, I think a "CAI"(after IAT) wouldt help to stay in lean burn till a certain point.
Becouse then you don't to give such alot of load and thus staying well below TPS 32%.
http://ecomodder.com/forum/showthrea...hx-8784-5.html
Has you probably know the IAT is located in the rubber inlet hose about 3inch infront of the throttle valve.
So Inlet manifold tempretures aren't measured directly.
This allows us to cool the intake manifold has much as possible, before freezing the fuel.
You only got to make a warm inlet for the warm-up period, making the evaporating pressure of the fuel less.

One could short cicuit the coolent lines throught the throttle body.
But the biggist heat source while in lean-burn is the EGR gasses.
I'm thinking of relocating the EGR inlet, from the exhaust valve hole to after the lambda or cat, making it possible to externaly cool the EGR gasses and prefend LB deactivation for warming the lambda.
What I saw while looking at the inlet and head, is that there runs a coolend tube/hole next to the EGR in the block, thus cooling it a bit.

Last edited by beer; 06-18-2011 at 03:08 PM..
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