This page lists some useful knowhow related to InputTrigger verification
The InputTrigger is the most important signal in the system. A multitooth trigger, especially the 60-2 contains an extreme amount of information that could be utilized for tuning. However, since many things can go wrong during an install, this page focuses on debugging, examining the trigger events that GenBoard sees (often during cranking attempts).
BMW S54 example: 3 triggers
(the red should be name "third trig", not "camshaft exhaust", because thirdtrig on this BMW is actually on the intake):
The relative times (changing because of compression forces) are indicated by the height (and the distance of pulses of course). note: Pulses were originally displayed with equal heights, like some examples below. Some important events, like spark positions are also displayed when enabled (enabled by default in VemsTune since about 2009, for each cylinder).
Other examples
Eg.
- inverted VR signal, also see GenBoard/Manual/VrSensor/Polarity
- unknown position of missing tooth
- noise ( GenBoard/Manual/GroundConnections )
- InputTrigger/RunOut
- new triggerlog implementation (since 1.1.78) can also log secondary trigger timestamps (and use CRC checksum)
- so the margin between secondary and primary trigger pulses can be measured without scope.
- This must be minimum 10 crankdegrees from the missing tooth (if a missing tooth wheel)
- or min 10 crankdegrees from the last tooth for other triggers, eg. coil type or InputTrigger/MultiToothNoneMissing.
- Except InputTrigger/AudiTrigger where it's quite close to the previous tooth (often around 1 crankdegree), that is OK.
- On newer non-PS2 firmwares the triggerlog can Log the Speed sensor signals and Spark events
- Note: the Speed sensor is not sampled continuously. Groups of 5 pulses seen. This is normal.
60-2 example log including secondary trigger data:
- missing tooth is 58 teeth after the previous missing tooth
- normally 532 (*4 usec) between teeth, but 1560 (*4usec) for the missing tooth, that is appr 2.93* longer (appr 3 since 2 are missing: good)
- sectrig pulse is 23 teeth (+291 * 4 usec) after the missing tooth (that is 23 + 0.55 toothtime), 116 teeth (=2*58) after the previous sectrig pulse
- file was made with VemsTune, Tools / Analyze,record triggerlog / from file
- file was made with brayterm Manmde40 command and 470 RPM signal, but new VT will be able to record from v3 (that worked earlier)
- I installed 2010-06-03 Nightly VT (if there is already a newer nightly, than the rest of the steps is not needed)
- renamed vemstune-c.exe to vemstune-cORIG.exe
- downloaded http://www.vems.hu/files/pacsa/vemsTune_2010-06-04_1024kPabugfix_exeonly.zip and unzipped into vemstune install dir
Under firmware 1.1.78 the trigger logging has different method, see:
See also