Possible Triggering Issues, Ignition Angle oscillates between -2 and 0deg BTDC

[arbartz95]

So, this is my first time using a Link ECU (FuryX), and my first time with this particular engine, so I'm very likely doing something wrong here.

The engine is a Polaris 2.0L, and has a 36-1 trigger wheel, with TDC on Cyl 1 occurring 11 teeth after the gap.  It has a cam wheel as well, however, it's quite odd.  It looks identical to the wheel shown here: https://www.bosch-mobility-solutions.com/media/global/products-and-services/commercial-vehicles/powertrain-solutions/natural-gas/camshaft-position-sensor/product_data_sheet_camshaft_position_sensor.pdf

So for right now I've just set Trigger 2 Sync Mode to None until I can get it to run on just the crank wheel.  

 

I've attached a high speed ECU log, and a Trigger Scope log of cranking.  RPM is extremely messy for the first second, but I assume that's just it trying to get sync, it then smooths out to a cranking speed that seems right (just under 300RPM).

I get no trigger errors other than when I stop cranking.  It seems to be fine, but the Ignition Angle sits around 0deg, and oscillates with the MAP signal down to -2deg.  I get pops out of the exhaust, which makes sense given the angle.  What I'm not sure of is why that is occurring.  So I'm thinking it's either a triggering issue, or some other value which I've missed.

 

Thanks!

ECU Log 2021-05-9 4;15;29 pm.llgx TriggerScopeLog2.llgx

[Adamw]

No, trigger looks ok.  The unstable RPM at the start of the log is because the RPM calculation is based on every tooth until it has "synced", then after sync the RPM calculatiopn is averaged over 1 or more TDC events (depending on the RPM filter setting).   So what you are seeing is normal for a low inertia engine that has quite unstable cranking speed.

Obviously it is not going to start reliably with no cam sync and direct spark ignition.  

You can use cam level sync for this engine.  Set trigger 1 sync tooth to 1, set trigger 2 sync mode to cam level.  This means the ECU will check the cam level at the first tooth after the gap every crank rev.  Since the tested cam level is high during one rev and low on the next the ECU can determine phase from this.

Since TDC is 11 teeth after the gap (approx 110 deg), your trigger offset will likely be around -110 or +250

 

 

 

 

[arbartz95]

Thanks for the quick response!  I hadn't considered the direct spark factor in my considering to remove cam sync to narrow down issues...

I added that back in, and made the changes you recommended.  I tried both -110 and +250, they are in the log attached.  -110 was done first, and heard some pops (much like I had heard before), but this time I saw spikes in the MAP signal, and it still would not run.  +250 was done second, and it just cranked continuously, with no pops or any signs of combustion.  

I think -110 is the right starting point, now I think I just may be needing to check everything with a timing light.  Interestingly, for the first time I've seen positive Ignition Value Angles that looked right when set to -110, so I think it's getting there.

Any tips or is checking everything with a timing light while cranking the next step you think?

ECU Log 2021-05-9 5;50;03 pm.llgx

[Adamw]

Timing light is the next step.  Note the logged ignition angle is just whatever is being commanded in your ignition table.  But it is irrelivent if the offset is wrong anyway.  

[arbartz95]

Alright I got a timing light and might have a clue why it's not firing.  I can barely get the timing light to work.  When I put the Ignition 1 output into test mode, the timing light flashes expectedly.  However when I go to crank the engine to actually check timing, it barely works, might get a flash here or there.  

This is leading me to think I have weak spark, which I'm hoping it just a calibration issue I screwed up, since these COP units and plugs are pretty much brand new.  

Have you seen this before, any thoughts?

[Adamw]

Do the coils have ignitors built-in?

 

[arbartz95]

Yeah, I'm fairly certain they do.  They are 3-Wire Delphi coils.  Factory wiring had +12V, GND, IGN.  

I decided to try the timing light on my truck ('04 Silverado) just to see if it works, and it worked, but was visibly missing some pulses, so I'm going to assume it's a timing light quality issue and not consider it too much.  (Need to get a better timing light in the future...)

I went back and tried wrapping the coil wire extension I picked up (so I could have something to get the timing light inductive pickup around), around the inductive pickup twice and could get somewhat consistent flashes, enough that every time it flashed I could see my timing mark was dead on.  

Pulled the plugs, cranked, saw fuel vapor.  Disconnected the injectors, pulled plugs and let sit on the exhaust, and saw sparks (albeit, "weak" looking). 

So I'm back to thinking I have something messed up in the setup.  Leaning towards it maybe being the Spark Edge.  I'm hesitant to switch the Spark Edge from falling to rising edge for fear of killing the coils, but at this point if I had it wrong I would've likely already burnt them out pretty good.

Going to sleep on it and see if there is something stupid I'm missing then try some more stuff tomorrow.

[Adamw]

59 minutes ago, arbartz95 said:

I'm fairly certain they do.  They are 3-Wire Delphi coils.  Factory wiring had +12V, GND, IGN. 

Can you measure resistance between the +12V and Ign pins.  If it is less than about 2ohms then there is no ignitor, if it is more than a few hundred ohms then they have ignitors built in.

 

1 hour ago, arbartz95 said:

somewhat consistent flashes, enough that every time it flashed I could see my timing mark was dead on.

You could still be 360deg out though, firing on exhaust stroke.  

[arbartz95]

+12V to IGN was 0.8Ohms, so you were right, there is no Ignitor.  First time I've come across 3 wire coils without an internal ignitor.  

So, that being said, it sounds like I'll need an ignitor module to get going here.  I guess the OEM ECU must have had the IGBTs and Ignitor circuit built into the ECU itself.  

 

And yeah, could still be 360deg out, but at least I know my timing isn't off from that.  

 

Thanks a ton for the help!  Learn more everyday...

[arbartz95]

Just to follow up, I got an ignitor, and she fired up!  +250deg was the correct offset.

Thanks again!