Ignition events missing
Some specifications:
- Firmware 1.2.31
- New install
- V8 with distributor ignition, simple trigger with HALL sensor, 4 points on the crank damper (evenly spaced 90 crankdeg)
- At idle 1000 rpm, it sometimes abruptly dies, as if turning of ignition key, and then resumes if you're lucky.
- No trigger error is displayed?
- Ignition events are clearly missing in a triggerlog of this event, why?
Owner will try enabling delayed reenable and HALL dirac filtering to see if it goes away.
- If there are no double pulses in triggerlog (zoom in heavily), filtering changes will most likely not help.
- Triggerlog 115200 (or even 19200) baud can transmit and capture all pulses upto redline RPM with this low toothcount trigger (only ~ 1300 bytes/sec or 600 pulses/sec at 9000 RPM),
- on the other hand (because no camsync) it might take more than 1 camshaft rotation during cranking at low RPM for first pulses to appear (suddenly many than), you prolly noticed this; that is OK.
Hello Mattias,
I have reviewed your vemslog and triggerlog, it seems you have configured an illegal tdc delay/angular width of tooth combination for simple trigger (without cam sync), tdc delay bigger than angular width of tooth:
- angular width of tooth = 90 deg.
- TDC delay is 107 deg (=90+17; so 17 crankdeg after next trigger pulse)
- should be max 89.5 crankdeg (45-60 is probably best if possible)
Possible solutions:
- trigger from rising instead of falling if that moves TDC delay down to recommended simple trigger 60deg.
- rotate your trigger wheel in a way that falling edge is @ (or around) 60 deg BTDC.
- It is very common to have one edge (the candidate is the rising edge in this case) at 80 .. 82 crankdeg, that is 8-10 BTDC ... Where such simple trigger was applied, factory engine management usually used that edge for cranking ignition timing (that is good engineering practice).
- actually dead-on spark timing during cranking is essential for kickstart motorbikes (even if this V8 is prolly not that kind :-)
- in the extremely unlikely case trigger HW cannot be set (with either rising /falling edge) properly to "TDC after the trigger" = 45..89.5 crankdeg, (but say 30 deg) it might require some config cheat (eg set 0..30 in spark timing table and cheat it to actual 10..40 BTDC). Should not be needed.
Best regards, Dave