EFI Myths answered.

Mark, that is some great information.
Thank you, it explains allot.
I'm sure I can do things with this.
Why cant you read the TPS voltage with a multimeter?

Mark_Donovan said:

Generally you could, but on the Berg the reading has to be taken with the ignition hot, there is no key switch unless yours is a street legal model. When you hook the XC1 tool it fires the ignition,but does not start the bike.

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Could I not just touch the button so's not to fire the engine, the ignition stays on long enough to take the reading?
Or bridge a relay?

Thank you for your info. My 2010 fe 390 runs lean. I'm in California. I've heard the 2010's generally runs lean. Are there different maps available? If so what would be the "map" to ask for when the dealer will re flash the ecu? Anything else I should know to get it right? Thank you.

Hi Mark,

Great post.

You mentioned in your first post that the map switches alters the ignition timing. Would it be possible for you to be a bit more specific about that?

For example, on the 2001to 2003 bikes, they came with a high/low switch, the low setting ******** the ignition timing up to about 5000 rpm if memory serves, and then after that the ignition timing was the same as the high map.

With the new bike, does it do the same, or does it affect the ignition timing all the way up to the rev limiter?

Thanks,

Dale

Great post Mark and a great subject heading, the Khein EFI system certainly is Mysterious (at least to me anyhow).

Interesting to know how the Khein EFI system learns 0% on the Throttle body, it is manually set by moving the TPS sensor and looking for 0.6Volts between ECU Signal Ground (Black Wire) and the TPS Wiper (Yellow Wire) by the sounds of what you are saying?

It is interesting you say the Khein ECU has an Altitude sensor because there is not one in the wiring diagram, and I was told there is no internal sensor in the Khein ECU. I know there is a Manifold Absolute Pressure Sensor (MAP Sensor), but it is connected to the inlet manifold and because of the way Husaberg send power to the Khein EFI ECU after the engine is spinning I can’t see how it can get an altitude reading when there is a vacuum in there when the engine is spinning. By “altitude” I am assuming you are saying Barometric Pressure?

Can you explain what the EFI is changing when it does this 5 min “initialization”?
It just frustrates me because I can’t comprehend that the Khein ECU can change a Fuel Map at idle for 5 minutes without even an oxygen sensor. Maybe I am misunderstanding something. The previous threads say “recalibrate” during this 5 minute period and by that I assume you mean change the settings in the Fuel map. This goes against the standard way to set a Fuel map in the Autronic ECUs that I understand, which is to use a wide band oxygen sensor and look at the Air/Fuel ratio in the exhaust to see if it is running rich or lean and then adjust those points in the Fuel map table to change the time the injector is open during an engine revolution. And by saying that it needs to be done at all point between the speed the starter motor spins the engine right through to maximum RPM and at loads from neutral to struggling in top gear up a hill. Not just by idling the engine for 5 min.

I understand that there is a Coolant Temp Sensor and an Air Temp Sensor. The Khein ECU should just read these sensors on the fly, and then apply a multiplier to the figures in the Fuel map table. Example when you first start the engine and it is cold the Khein ECU should look at the Coolant Temp Sensor and then hold the injector open by a factor of say 1.5 times longer than the Fuel map setting says for that load point. Same with the Air Temp sensor, just a straight multiplication factor. They can even look at Coolant Temp and Air Temp together and estimate what the air temp is when it is passing through the cylinder head, but then the result should be a multiplication factor to the original Fuel map table I don’t see a need for an ECU to sit around waiting for 5 minutes to recalibrate something. So tell me what that something is?

I am guessing the MAP Switch must change the rate of attack of the timing too on the 3 different settings. Not just the actual degrees. Just a guess

With regard to the to the map switch. I have some experience with EFI on cars, it was a while ago but I assume things haven't changed that much. But we used to change what we called a "tune resistor". This would be change for different reasons, but they were labeled for different areas, so I can only assume it had something to do with emissions.
It would alter both the fueling and the ignition, I assume by altering something in the base parameters. It would be good to know how the map switch changes things in the Khein EFI system. I could then understand some of the problems i'm having. I think I'll get it dialed out with the TPS and Idle settings.

Mark_Donovan said:

I just found this on Wikipedia and may indicate a relationship between a MAP sensor and altitude. Maybe I misunderstood Al?

The following example assumes the same engine speed and air temperature.

* Condition 1:

An engine operating at WOT (wide open throttle) on top of a very high mountain has a MAP of about 15" Hg or 50 kPa (essentially equal to the barometer at that high altitude).

* Condition 2:

The same engine at sea level will achieve 15" Hg of MAP at less than WOT due to the higher barometric pressure.

The engine requires the same mass of fuel in both conditions because the mass of air entering the cylinders is the same.

If the throttle is opened all the way in condition 2, the manifold absolute pressure will increase from 15" Hg to nearly 30" Hg (~100 kPa), about equal to the local barometer, which in condition 2 is sea level. The higher absolute pressure in the intake manifold increases the air's density, and in turn more fuel can be burned resulting in higher output.

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On some systems the MAP sensor will be labeled the absolute pressure sensor. All you need is the mass of the air. I'm trying to think back to my Crypton and Sun tuning courses. I'm going to go and dig out some old books :roll: :?

Hey Mark,
There was some banter about Khein ECU maps a while back and it seems the Khein ECU only uses TPS and Engine RPM for the main Fuel map table after the Throttle is opened more than 6%. It uses MAP sensor and Engine RPM when Throtle is under 6% open.
I was told the Khein ECU does this because the Inlet Manifold on the Husaberg is so small the MAP sensor cannot get an accurate reading in a small space that is so close to the valves opening and shutting and reverberations. So I am not even sure if the MAP sensor is used after 6% Throttle openings.

tahoeacr said:

MAP vs RPM is used below 6%TPS. TPS vs RPM from there on out.
The idle trick as I prefer to call it probably takes so long as the ECU probably needs to see 160 or 180 ECT's. With the 990 you are suppose to let it run until the fan kicks on(215F). The burn in I believe is just the initial start up with the dealer. All LC-8's have the same ECU. When serviced, the dealer programs in what bike it actually is, and adds the appropriate map.

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viewtopic.php?f=26&t=11554&

It would be really handy to know what is actually adjusted in the 5 min burn in.

nick790 said:

Mark_Donovan said:

Generally you could, but on the Berg the reading has to be taken with the ignition hot, there is no key switch unless yours is a street legal model. When you hook the XC1 tool it fires the ignition,but does not start the bike.

Click to expand...

Could I not just touch the button so's not to fire the engine, the ignition stays on long enough to take the reading?
Or bridge a relay?

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Hi Nick790, There is a 6 pin plug under the seat that is not connected to anything. Take the cover off the plug. Short out Pins 5 (Black/White Colour wire) and Pins 6 (Brown Colour wire). That will turn the ignition on and fire the EFI ECU up. This must be what the XC1 tool does as it plugs into that connector.
You can do a test first and pull out Fuse 2 (Fuel Pump Fuse) before shorting out pins 5 and 6 and you will see the FI Light flash the Fuel Pump error. So it is a good way to check wiring on the bike if you need to keep the ignition on

Thanks Davo, i'll do it that way. :wink:

Mark_Donovan said:

Davo I'm making a list to bend their ear when I call back. If the MAP sensor is only utalized below 6% throttle, maybe the "don't touch the throttle 5 min initialization' is when the map readings make any difference. Perhaps at idle it provides a more stable reading. Have we decided if that reading could be perceived to change based on barometric pressure?

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I can understand the info you found in Wikipedia. When the Throttle is wide open (WOT) the Map Sensor which is connected to the inlet manifold can get a better reading of Atmospheric Pressure because there is a “clearer” path to the outside air with the butterfly in the Throttle body open all the way. But I cannot get my head around the MAP sensor getting an Atmospheric Pressure reading when the Butterfly is closed and the air is coming through a very small hole.

That Wiki thing you found pretty much said at sea level and wide open Throttle the MAP sensor should see about 14.7 psi and half that (7.3 psi) at a high elevation.
If you apply that Wiki theory to the Husaberg idling with the Throttle Butterfly shut would the MAP sensor see that difference of 7.4 psi (14.7 – 7.3) at different elevations, when there is already some vacuum in the inlet manifold. I don’t know the answer to that but I would guess no. I can’t even test that on my Autronic in my boat as it is only ever at Sea Level.

The real question to ask the KTM Techs is what is the Khein EFI recalibrating?
It can’t be the Fuel Map as it has no Oxygen Sensor to check any Air/Fuel Ratio measurements.
It can’t be Altitude as the Map Sensor is behind the Throttle Body in the inlet manifold and the Butterfly is shut so it would be impossible to get an accurate reading. (I could be wrong on this).
It actually can’t be much of anything at idle as the EFI would need to read it’s engine sensors at a particular Engine RPM and Load (Load being MAP sensor presure or TPS Position) to even know what to change.
You might as well ask them does the Khein EFI, as it is set up in the Husaberg, make any compensation for Altitude. I am guessing no, as it uses the TPS as the Load axis on the Fuel map after 6% throttle opening and it can’t get an accurate reading from the MAP sensor for Barometric Pressure before the engine starts, as the engine is spinning before the ECU receives power so there is already vacuum in the inlet manifold.

I am guessing the instructions that the dealers get to do this “Burn in” is based on a closed-loop EFI system as used on previous KTM Khein EFI Bikes with:
* Oxygen sensors that can provide feedback to the Fuel Map table after the engine has warmed up (might explain the 5 min period).
* Possibly a second type of pressure sensors to measure barometric pressure.
* Elaborate Throttle Bodies with Electronic butterflies and idle up solenoids. The Husaberg is a plain and simple Throttle body with no Electronic gizmos in it that are controlled by the Khein EFI ECU.
* Possible Knock sensors.

In summary I believe the Khein ECU as it is setup in the Husaberg is setup in an open loop EFI mode that cannot recalibrate a Fuel or Ignition map because it has no useful information to do this, especially at idle. I reiterate, Temp Sensor and Air Temp Sensor should just be a Multiplication factor on the base Fuel and Ignition map settings which can be done on the fly at any engine speed or load, and not by sitting for 5 minutes at idle.
Reminds me of when I was younger and raced a 350 Chev in my ski race boat. Timing was set by making a mark at 30 Degrees on the flywheel and reving the engine to 3,500RPM and setting the timing at 30 Degrees. Jets in the Holley were set by holding the boat flatout (we didn’t have WOT acronym back when I was young) at 6,200RPM for a few minutes, turn the ignition off and pull out the plugs and making a judgment on what jet sizes to run based on plug color. Everything "of importance" was changed at the speed we would run the engine at not at idle.

In the 1 year I have owned my FE570, I have never let my bike idle for 5 minutes and never will. Again, I am happy to be proven wrong and by all means let me have it with both barrels when you correct me. I am here on UHE to learn.
What is your favorite drink Mark? I love your southern accent that I heard on a post you did ages ago with some children riding with you.

Davo said:

In the 1 year I have owned my FE570, I have never let my bike idle for 5 minutes and never will. Again, I am happy to be proven wrong and by all means let me have it with both barrels when you correct me. I am here on UHE to learn.

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I certainly can't converse with you on the technical aspect of the EFI, you have a much greater understanding of this that I ever will. But from experience I can tell you that 'initializing' does make a difference. I had 'initialized' my bike a number of times, 2500 ft, varying temps to 8000ft and varying temps....with no real difference, it always ran well. It was not untill this past September when I rode our national enduro series, and was warming myself up on a test loop that I found my 570 lean poping on decel and detonating when lugging the motor. This had NEVER happened to me before. For poops and giggles I 'initiallized' the bike and it ran better, but not perfect. After the first loop, once the motor was good and hot, I did it again, and it ran perfect. This venue was sub 700 ft, similar temps but way higher humidity, thus varying air density.

I don't know why, frankly don't care too much about how it all works, I just know that it does. Way easier than spinning jets :cheers:

fry