Ignition Time Delay Setting?

Post Reply
Jason Bentley
Posts: 29
Joined: Sun Jul 02, 2017 6:17 am

Ignition Time Delay Setting?

Post by Jason Bentley »

I've learned that some ECUs have a compensation table for ignition delay. This is the time/delay for the ignition to actually fire from the time it was enabled by the ECU and is dependent on the ignition system and coils. I've been told, for my application, it should be around 20ms.

I'm experiencing a timing drift when I have my Ignition timing locked. I"m seeing this with my timing light, as I rev my motor up through the rpms. My timing retards 5° while locked at 10°. I have confirmed my VR sensors are wired correct, tried swapping trigger sides between falling and rising and verified my cam isn't drifting via the camRaw value.

Anything I'm missing?
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: Ignition Time Delay Setting?

Post by stevieturbo »

What crank trigger are you using ? That is what will control/reference timing, not the cam trigger.

Any odd voltage trigger thresholds ?

I know the setting you refer to on other ecu, but I've never noticed anything that resembles in on Syvecs. Perhaps teeth gap widths might be something to do with it ?

It'd really be a question to ask Syvecs directly.
MReilly
Posts: 33
Joined: Fri Jan 19, 2018 7:05 pm

Re: Ignition Time Delay Setting?

Post by MReilly »

Yeah Motec and Link have that setting, probably others too.

I think you effectively just "bake it in" to the main table on ecu's that don't have it, which might not be exactly what you wanted to hear, and not really all that correct in reality.

You could maybe use the individual cylinder trim table to create a correction for it over rpm? Set your base table to your locked value and then tweak about on the cyl trim vs rpm table until she follows the commanded timing. At least that way your main table reflects a more correct timing value. If you were really anal about it you could check each cylinder does the same thing too, and correct for it if they don't, you'd need a 180* out TDC ref for that though.

Would be nice if the Syvecs staff could clarify if there is some way of setting this we aren't seeing?

Just to confirm though, you aren't using one of those lights with the advance dial set anywhere other than 0, and you aren't running wasted spark?
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: Ignition Time Delay Setting?

Post by stevieturbo »

I think he's just saying the timing light moves on transients....not that anything is incorrect at any particular static load site.

And yes, potential lag in a dialback light may also be what is being seen ?

So whether what is being seen is a red herring or actual incorrect timing....you'd really need to reference crank position to ign output with a scope to see if it is moving
Jason Bentley
Posts: 29
Joined: Sun Jul 02, 2017 6:17 am

Re: Ignition Time Delay Setting?

Post by Jason Bentley »

Thanks for the feedback, fellas.

Just to clarify - I am referring to a "drift" during transition during an quick increase in engine rpm. I am using a dial-back timing light and confirmed my dial-back setting is at 0°. I've also utilized this feature to confirm my static reading at 4000rpm is correct as well. So, as Stevieturbo mentioned, I am only seeing this "drift" during transition.

I have reached out to Syvecs Tech Support. At the time, I had a HKS DLI ignition system wired in, but I have since removed that after speaking with Syvecs. The HKS DLI was there before I installed the Syvecs, but just realized it needed to come out once I spoke with Ryan of Syvecs. Removing that did not make a change in the error I'm seeing.

I have tried everything - reversing polarity on wiring of cam and crank sensors as well. Has anyone else experienced this with their Syvecs ECU? Is is safe to move forward with tuning my car?
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: Ignition Time Delay Setting?

Post by stevieturbo »

Again, the only way to verify would be comparing crank angle to ignition output on a scope to see if it is actually changing as you think

I guess if end of injection timing was a constant ( which it mostly should be ), you could scope on cyl1 that and throw a current clamp onto cyl1, maybe set timing to a fixed number on the table and see of the scope traces do deviate, or stay in sync.
MReilly
Posts: 33
Joined: Fri Jan 19, 2018 7:05 pm

Re: Ignition Time Delay Setting?

Post by MReilly »

If it's just during the transient event and is actually in the retard direction then I really doubt you would cause any harm to the engine with it if it is a true timing variation, in fact a lot of ecu's allow you to do just this to try to allow you to reduce tip in knock.

I think it will actually be caused by your timing light. Not certain on this, but I think that dial back lights use the time between the current and the last ignition pulse to figure out when to fire the next, to allow you to use the dial feature. It has to predict the next event so that you can vary it away from that with the dial, and I don't think that this changes if set to 0*. So if the engine speed varies during the sample time it will then be off until the speed stabilises again, hence you see the drift.

If you still want to properly figure it out then I'd try what Stevie suggests, that should give you 100% certainty if you use the actual crank sensor as reference. However, I am fairly confident that it's probably a misread with the light, and that if that isn't the case that you will not harm anything with a slight timing retard during transient increases in rpm or load anyway.
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: Ignition Time Delay Setting?

Post by stevieturbo »

MReilly wrote:If it's just during the transient event and is actually in the retard direction then I really doubt you would cause any harm to the engine with it if it is a true timing variation, in fact a lot of ecu's allow you to do just this to try to allow you to reduce tip in knock.

I think it will actually be caused by your timing light. Not certain on this, but I think that dial back lights use the time between the current and the last ignition pulse to figure out when to fire the next, to allow you to use the dial feature. It has to predict the next event so that you can vary it away from that with the dial, and I don't think that this changes if set to 0*. So if the engine speed varies during the sample time it will then be off until the speed stabilises again, hence you see the drift.

If you still want to properly figure it out then I'd try what Stevie suggests, that should give you 100% certainty if you use the actual crank sensor as reference. However, I am fairly confident that it's probably a misread with the light, and that if that isn't the case that you will not harm anything with a slight timing retard during transient increases in rpm or load anyway.
Although as injection timing also references off crank trigger....I guess maybe scoping against the cam trigger might be a more solid approach ( assuming not a variable cam timing engine )
Jason Bentley
Posts: 29
Joined: Sun Jul 02, 2017 6:17 am

Re: Ignition Time Delay Setting?

Post by Jason Bentley »

[img]
MReilly wrote:If it's just during the transient event and is actually in the retard direction then I really doubt you would cause any harm to the engine with it if it is a true timing variation, in fact a lot of ecu's allow you to do just this to try to allow you to reduce tip in knock.

I think it will actually be caused by your timing light. Not certain on this, but I think that dial back lights use the time between the current and the last ignition pulse to figure out when to fire the next, to allow you to use the dial feature. It has to predict the next event so that you can vary it away from that with the dial, and I don't think that this changes if set to 0*. So if the engine speed varies during the sample time it will then be off until the speed stabilises again, hence you see the drift.

If you still want to properly figure it out then I'd try what Stevie suggests, that should give you 100% certainty if you use the actual crank sensor as reference. However, I am fairly confident that it's probably a misread with the light, and that if that isn't the case that you will not harm anything with a slight timing retard during transient increases in rpm or load anyway.
Thanks for the feedback. I have thought of what you're mentioning, as far as not causing any harm to the engine if it is a true timing variation in the direction I'm seeing. If what I'm seeing IS a true and accurate event, my only thought/concern is that I find it strange that the ECU doesn't actually know where the engine is in the cycle when firing the ignition. I think very highly of this Syvecs ECU and the people behind it, so I'm really leaning on the side of operator error here. I'm going to purchase a non dial back timing light and see what happens there. My timing light is setup for a direct fire ignition system, but does have the option for wasted spark as well.

I'm happy to attach and share any log files that may help diagnose this issue. Thanks again for everyone that has taken the time to respond. I'd also like to share that I do have a Tuner I trust helping me. He's aware we CAN tune the car, but this is his first time with the Syvecs ECU so we just really want to be sure there's not something we're missing in the setup. He has showed me the compensation table I'm asking about in the Motec, AEM Infinity and even ECU Masters software. Does anyone have time to check to see if this "drift" happens to them with their Syvecs under the same conditions (with Ignition Output Test Mode enabled) ?
Jason Bentley
Posts: 29
Joined: Sun Jul 02, 2017 6:17 am

Re: Ignition Time Delay Setting?

Post by Jason Bentley »

I just wanted to share a response from Syvecs Tech Support to everyone who is interested and has helped with me on this post; The Syvecs does not have this function, but I'm glad to hear it's safe to proceed with my tune:) Thank you to all for your input.


Again - my Tuner and I were only being cautious as it's our first go with the Syvecs ECU.
Post Reply