roger 04 rt
New member
I'm willing to accept for the moment that on sensor is primary for spark and the other for fuel. But which ever sensor is used, the Motronic has to have a calculation for crankshaft rotational speed and rotational acceleration or deceleration.
That means whether the sensor is top or bottom for spark, that calculation is making a calculated guess about the future to come up with, the time that the crankshaft will be, say, 43 degrees before the next sensor.
One sensor can do the job. Two sensors mean that the period you have to guess about is half as long. It also creates the possibility to fire the injectors twice when the engine is cold, at slow RPMs. Since it could run on one sensor, the question. In my mind is what the Motronic software does when one signal opens or when the two signals cross-talk with each other.
In that case the bike may just stop, but there's equally the chance the the Motronic just does what it can with the working sensor, or the one it thinks is working
Cross talking may explain a group of difficult conditions.
For example my bike runs great and starts okay, but doesn't start quite as well as it did 6 months ago.
Here is what I'm seeing:
In the green shaded area, on the first start of the day, the mixture is leaner than it should be. The second start and all other operations (e.g. Cruising, accelerating) of the motor are fine. All the sensors work, there are no error codes, every aspect of the fuel system and injectors has been tested. (The bike even idles nicely with one injector pulled for spray pattern test!)
The only thing I can measure is that for the first ten seconds the engine is lean, and that when this happens the spark advance stays at zero for 10 seconds. See in the chart how long after the rpm is increasing before the spark advance increases. That isn't usual (like the first 10 seconds of leanness).
I've measured the HES with the GS-911 and each sensor will fire but not always in a 12121212 pattern while turning the engine over by hand. It usually goes 12212111212111212112, etc. I don't know if that is due to my uneven rotation of the crank when using the rear wheel.
So I'm deducing at this point that my HES has a subtle problem that is keeping the injectors from firing correctly during the first ten seconds. The GS-911 is reporting the correct length injector pulse.
After the first 10 seconds everything is fine. And if the bike is even a little warm everything is fine. It's a really interesting set of symptoms.
My next step is a physical inspection of the HES and then a replacement sensor.
RB
That means whether the sensor is top or bottom for spark, that calculation is making a calculated guess about the future to come up with, the time that the crankshaft will be, say, 43 degrees before the next sensor.
One sensor can do the job. Two sensors mean that the period you have to guess about is half as long. It also creates the possibility to fire the injectors twice when the engine is cold, at slow RPMs. Since it could run on one sensor, the question. In my mind is what the Motronic software does when one signal opens or when the two signals cross-talk with each other.
In that case the bike may just stop, but there's equally the chance the the Motronic just does what it can with the working sensor, or the one it thinks is working
Cross talking may explain a group of difficult conditions.
For example my bike runs great and starts okay, but doesn't start quite as well as it did 6 months ago.
Here is what I'm seeing:
In the green shaded area, on the first start of the day, the mixture is leaner than it should be. The second start and all other operations (e.g. Cruising, accelerating) of the motor are fine. All the sensors work, there are no error codes, every aspect of the fuel system and injectors has been tested. (The bike even idles nicely with one injector pulled for spray pattern test!)
The only thing I can measure is that for the first ten seconds the engine is lean, and that when this happens the spark advance stays at zero for 10 seconds. See in the chart how long after the rpm is increasing before the spark advance increases. That isn't usual (like the first 10 seconds of leanness).
I've measured the HES with the GS-911 and each sensor will fire but not always in a 12121212 pattern while turning the engine over by hand. It usually goes 12212111212111212112, etc. I don't know if that is due to my uneven rotation of the crank when using the rear wheel.
So I'm deducing at this point that my HES has a subtle problem that is keeping the injectors from firing correctly during the first ten seconds. The GS-911 is reporting the correct length injector pulse.
After the first 10 seconds everything is fine. And if the bike is even a little warm everything is fine. It's a really interesting set of symptoms.
My next step is a physical inspection of the HES and then a replacement sensor.
RB
