Currently trying to get my car to idle, it has been close, but fuel was all over the place. After a bit of digging we found that the “Primary Unexpected missing teeth” number was going up any time the engine was turning over.
Obviously this isn’t what we want, but we can’t figure out why it is happening. The sensor was replaced, pretty much every sensor setting was tried (pullup, pulldown, threshold voltage, filters), and we reversed the sensor wiring. The sensor is wired to digital 1 and digital ground, just double checking it shouldn’t be connected to sensor ground.
I have linked a log while it was having trouble, as well as a scope and tune. The scope looks how I would expect, but it is still getting the missing tooth number. The number is also totally different each time, so it seems to be completely random.
This was on firmware 222.0 (beta), is this a known problem with this firmware version?
Just looking for some guidance, as this problem has us stumped.
Hi,
The “Primary unexpected missing teeth” channel is a bit misleading in this case.
The first thing to fix is the secondary trigger.
You have to change the edge for the secondary trigger or select a different sensor.
One crank revolution is selected in the picture below.
Every next revolution looks exactly the same.
You can’t synchronize to one of the two revolutions if both are identical.
Perfect, thank you. We were definitely looking in the wrong place.
Makes sense that it doesn’t know where the engine is if every 720° is split into two 360° sections that look identical.
I’ll see what I can do about it though, as that’s the factory cam trigger, so no idea how the factory ECU does it. Possibly a combination of both cam sensors?
EDIT: nope, sensor on the back of the cam gear for factory trigger
Either way, thank you for your help and fast response.
I have a further question that I’m hoping I can resolve in here rather than creating a new thread.
I have now added a third cam sensor to the back of the AVCS gear. This has two teeth, the spacing puts them at crank tooth 17 and 33 on the scope. I was using N+1 and got the car to start, but it now is really hit and miss as to whether it wants to sync, or it is really slow to sync.
The settings are a default option in the Classic and Black software, so I wasn’t able to just copy those settings.
The teeth are as below. Scope all looks consistent (scope attached). Just feel like there is a setting that’s not right and causing the sync to not be quite right. Is there also a setting in the PRO for wasted spark while syncing/cranking?
