kimdrummel wrote: ↑
Sun Mar 27, 2016 9:14 am
… the Toyota 24 + 2 (should we call it that?)
If this unusual combination is addressed in code, it would likely be designated Toyota 24/1/1
, to both hold to naming convention and which highlights it is not like other typical systems.
Per the Wiki, the first number is the primary wheel teeth or pulses (24). The character "+" means additional teeth are present on the wheel, which is not the case here. A couple examples of "+" wheels are here
. A "/" character signifies the following number(s) are cycle pulses. As there is only one cycle tooth, but two cycle sensors; each outputs one pulse-per-cycle, ergo 24/1/1.
Part of my point in this is to highlight some of the causes for issues in decoding using the current decoder methods. Cycle pulses are per 720° in order to signify the cycle the engine is in, allowing sequential identification. However, if both cycle sensors are connected, then it violates the assumption that cycle pulses are in specific places. With the cycle pulses every 360° from two sensors, Speeduino does not know which is correct and it also does not expect another one in the same cycle, leading to processor confusion that it should occur 720° apart or at least within the same 360° crank rotation.
To add to the mess, all three sensors share grounds. This tends to cause "ghosting" signals which can confuse the VR conditioner. So, even if you do not connect one of the two cycle sensors (making it a good 24/1 setup), the VR module may still 'see' the 2nd sensor ghost signal though the shared wiring, as shown in some 'scope images. Some suggested workarounds are to ground the unused cycle sensor signal with a low-value resistor, and/or ground all sensors off-board so the module only sees positive module inputs more like a Hall or optical signal, or remove the second cycle sensor (if possible).
To add one more issue that prevents easy application of this Toy distributor is the signals, which could "work" with Rising
setting for crank (careful with your module's signal inversion
), but (depending on conditioner) may work better with opposite
edge on the secondary cycle signal. I have not had enough time with one to test what the golden combination is, nor even to verify the polarity of the signals is what the system expects. This would of-course cause issues to those removing primary wheel teeth.
As the original poster's images are no longer working, some fresh 'scope images of the three sensor outputs would be very helpful at this point for analyzing the Toyota 24/1/1 decoding and settings options. We need reliable information in order to tell Speeduino what to do with it. Any volunteers?