Trigger 1 making no sense

[Island_Racer]

Can anyone look at these logs and explain to me why my trig 1 (crank) is doing what it is doing.

Some background:

- the wire is shielded 1/2 inch from both the ecu pin and the sensor.

- the sensor is positioned in the dead center of the toothed wheel.

- the trig 1 (crank) and trig 2 (cam) are both sharing the same sensor supply (5v) and sensor ground. cam sensor never loses signal...ever.

log 1: https://www.mediafire.com/file/cybsg77svh90ps2/random_trigger_1_signal_loss_1.llgx/file

log 2: https://www.mediafire.com/file/ytwuecaiof01tfp/random_trigger_1_signal_loss_2.llgx/file

log 3: https://www.mediafire.com/file/lkhh3kud7vqjhia/random_trigger_1_signal_loss_3.llgx/file

log 4: https://www.mediafire.com/file/6czhocp42m6nclw/random_trigger_1_signal_loss_4.llgx/file

[Adamw]

Its not losing signal, you have a trigger error so the trigger state returns to blank time before it resyncs.  

Can you provide a trigger scope capture at about 2-3000RPM, a copy of the tune and some info about the trigger and engine. 

[Island_Racer]

Adam,

I tried saving a capture but when i open it it keeps opening differently form how the capture looks (maybe you can configure it)

See attached the tune, the scope log at idle and scope log at 2K (tonight it didnt "lose signal" as much as last night but i added some other logs where i couldnt even pass 2K rpm due to the trig signal going away.

I currently use the Racer X Fabrication crank and cam trigger system (36-1 wheel) with a cherry sensor and the airgap is 0.060" and for the cam, the single tooth and a cherry sensor on that as well.

 

Because the scope looked different from the file when i open it please see screen shots for the scope itself:

image 1: https://www.mediafire.com/view/bxh7jvn4rxfkora/trigger_log_1.jpg/file

image 2: https://www.mediafire.com/view/qbzlsenan73gy8f/trigger_log_2.jpg/file

 

My engine is a 3rd Gen 3Sgte head and a 5S block and the expected components for a fully built motor.

trigger scope 1 (2K rpm).llgx trigger scope 1 (idle).llgx Current Map for Stefan.pclx TriggerScopeLog other 3.llgx TriggerScopeLog other 2.llgx TriggerScopeLog other 1.llgx

[Adamw]

Those triangle "holes" at the bottom of the trig 1 waveform occur every 180 deg and peak right about where TDC would be for each cyl.   My first thought was you have a wiring issue causing starter motor current to pass through the ecu ground or similar.  But then I noticed the same effect is present in your "2K RPM" scope so I think that rules out the starter motor.  The only other item I can think off that would pull current around every TDC would be the ignition coils.  So I would start by inspecting carefully where the coils are grounded, where the crank sensor is grounded, confirm both have very low resistance from their plugs back to the main star ground point.  Actually, a quick test you could do is unplug the coils and do another cranking scope to see if those triangle holes have disappeared.     

A further thought - I would confirm the wheel is actually running true too, especially axially. You probably dont need to go as far as physically measuring it, just get someone to crank it over while you watch it to confirm there is no wobble.  

 

 

[koracing]

I'm not a fan of this trigger wheel kit as I've seen others have issues with it as well.  Maybe sensor orientation has something to do with it?

[Island_Racer]

Adam,

   Pulled the coils and cranked….perfect square wave. So i ran a new ground for the coils and everything is sorted now.