RobinHodges

Here's the section of the help file that states only the 1st tooth after the gap is used to check the cam sensor state:
 
"·The level of the sync signal is sampled only on the tooth after the gap on the crank signal. This means that the level of the sync signal at other crank positions is irrelevant. For this reason a signal with more than one tooth can be used on the cam as long as the signal level is high at the tooth after the gap on the crank signal on one crank revolution and low on the next crank revolution.
 
·When the tooth after the gap occurs on the crank signal, if the sync signal is low, engine position is set to 0 degrees plus the trigger offset. If the sync level is sampled high on the tooth after the gap then engine position is set to 360 degrees plus the trigger offset."

Hi all, 
I have a BMW M50B25TU engine, with a VR crank sensor and a hall cam sensor. ECU is a G4x Storm. 
I'm hoping you guys can give me some tips on configuring my triggers. 
While I'm aware there is a base map for my engine for the G4x, I need to be absolutely certain my understanding of the trigger setup is correct due to a suspected misaligned crank trigger wheel.
While making a mark with white paint where the TDC mark is on the crank trigger wheel (to use with a timing light), I noticed cylinder 1 was a long way off actual TDC (maybe 30 degrees or something).  I've since made my own mark to use at real TDC.  With this new TDC mark - I managed to establish a timing offset value of -261 degrees (not what's stated in the base map for my engine).
I've included a screen grab of my crank and cam sensor outputs on the Trigger Scope.  From other scope traces I've seen, mine is indeed offset (trigger wheel misaligned).   I assume this isn't a problem - it just needs setting up!
When it comes to setting up the cam sync, from what I've read in the help file I should be using Sync Mode = Cam Level.  I think this is because I have a hall cam sensor (steady state voltage on a square wave).
The question I have at the moment is what is the purpose of the Sync Tooth in the Trigger 1 setup?   I thought this was where the ECU looks for a cam pulse (e.g. if you have a VR cam sensor generating a single short pulse).  
For Sync Mode = Cam Level, the help file indicates that only the 1st tooth on the crank after the missing tooth is used to sample the cam sensor state. So setting the Sync Tooth does nothing in this case??
I've no doubt missed the point here. 
Just to throw in additional complication, to ensure the Vanos cam angle shift won't affect things surely I want the ECU to sample the cam level pretty much bang in the middle of the square wave? (give maximum movement each direction)  That would be roughly on the 20th tooth after the gap on the crank trigger. BUT - apparently only the 1st tooth is used?
The map currently uses a Sync Tooth value of 49 which is where the cam level goes high, low.  This was a stab in the dark and probably wrong. Clearly sampling here will be on the cam sensor transition, and not on a steady state value. 
Map, Trigger Scope log and screenshots attached. 
Thanks guys!
(p.s. I am aware about the need for igniters with this ECU. Audi R8 coils standing by. I'll measure base timing again once fitted)
 
 
 
 
 
 


map_3.pclx trigger_scope_2.llgx

Thanks guys for the quick response! 
I have to say the help documentation is some of the best I've ever seen for a bit of control equipment.  Keep it up! 

Thanks guys for the quick response! 
I have to say the help documentation is some of the best I've ever seen for a bit of control equipment.  Keep it up!