BMW S50B30
I have an issue where after 5500 rpm the third trigger position goes higher, a bit erratic, about 90 degrees higher than where it actually is. Load on the engine doesn't matter, happens free revving as well.
It's not clear to me, but but it could be false triggering (noise) on third trigger input? I may hook up my Rigol scope and check it out. SDA input has 10k resistor in-line, 10nF towards ground and 1N4007 diode for protection.
Details below.
Hardware setup
- Third trigger : 8 points on intake cam equally spaced.
- Second trigger : 1 point on intake cam.
This is the most retarded position (at rest, cranking) :
Software
Download [triggerlog] and [vemslog]
The measure tooth can be set to 0 or 15 to reach as low angle on the third trigger as possible, 5-35 degrees is recommended. At rest (most retarded) the third trigger occurs at the missing tooth, and every 15 teeth. I've tried other measure tooth settings (0-15 is all that is possible) and I still get this same problem.
Log view of free revving the engine
