Too man primary triggers and secondary trigger error - trigger log attached

[Grant]

Hi guys,

Car is a 16V 4AGE with ITB's and cams, running off of a GZE 24+1 CAS on the exhaust cam. 

I actually am starting to drive the car around and map it, but I think I may be getting hesitation up high. 

The weird thing is there is a trigger error the entire time, ever since the car first fires up...I'm actually surprised it is even running as the ignition and fuel is sequential.  I thought it would need the secondary trigger for that. 

Below is the output at idle. 

Falling
TDC after trigger - 73 degrees
24 Teeth
0 tooth is 4 teeth after TDC
Nearest tooth is 6
Angular width is 30 degrees

Secondary
Rising
Single edge while cranking
Filtering disabled

What does too many primary triggers mean and how should I try and fix a bad secondary trigger position?

First photo, I disabled one of the errors so you can see the secondary trigger line that it is on top of.
Both images were taken at the same point in time.











Thanks all!

[VEMS]

Hello Grant,

"Too Many Ptrig" means the ecu sees more tooth per cam cycle than configured in the configuration. This can mean either noise injected into trigger signal (cross current, capacitive coupling or other) causing uneven or additional primary or secondary trigger, but since your triggerlog (visual) shows even tooth times this is less likely the problem. The most likely in your case is configuration error, could you post your vemscfg so i can review ?

Best regards,  Dave

[Grant]

Hi Dave,

Nice screen name.

I hate to do this to you but I can't find anywhere on this BB where I can attach a file?  How do people normally upload their configs?

Thanks,
Grant

In the mean time here is a screen capture:





 

[VEMS]

Hello Grant,

After taking another look at your configuration and picture of trigger hardware i would like to suggest the following:

1) Change primary trigger edge to rising (as suggested with vr trigger).
2) Swap wires from the secondary trigger sensor (VR+/VR-).

The secondary trigger pulse is very close to the primary (sometimes overlaps) this will lead to race condition which is seen first, hence the trigger error.
Swapping polarity on the secondary trigger should solve that. Please post another triggerlog afterwards to confirm.

Uploading of files to the forum directly is not possible, but you use the VEMS file area: http://www.vems.hu/wiki/index.php?page=FileArea and link to that.

Best regards, Dave

[Grant]

Swapping the polarity on the 2nd trigger make sense, as I had to swap it in the first place to get the POS AEM EMS-4 to work on a rising/falling edge signal (I forget which one it was, but AEM EMS-4 only works on either rising or falling...so I had to re-wire the CAS).  Maybe that caused the signal overlap. 

So you are saying that on a normal CAS with cam sync, it is important for the secondary to not overlap on a primary? 

I believe the car ran worse when the primary was set to rising. 

[VEMS]

Yes, very important. Since there are no missing tooth on your trigger setup the only way to synchronize the engine is to sync to the first tooth after cam pulse, if the cam-pulse sometimes comes before and sometimes after, you can see where things will start to go sour. The ecu will however recognize this and attempt to resync (and flag a trigger error).

But to be frank it is imperative that cam pulse never overlaps the primary trigger pulse. I suspect the primary rising caused a bit more overlap (without changing secondary) but vr= rising is preferred and recommended.

Regards, Dave

[Grant]

Thanks a lot Dave for explaining this.  This will certainly help me in the future (I do about 3 installs with various systems a year). 

I ill be sure to update after I get this sorted out.

Thanks,
Grant

[Grant]

I got home after work and proceeded to swap the secondary trigger wires.  I also set primary and secondary to FALLING edge.

Now the Secondary is no longer overlapping a primary trigger event, but the same errors were still being reported - Too many primary triggers and secondary trigger errors. 

The other clue was that there were only errors showing as soon as the engine fired...while cranking there were no report of errors.  I was beginning to think it was a noise issue.  I added a variable pot accross 2nd VR+ and 2nd VR- and adjusted between 0-500ohms with no improvement. 

I was pretty stumped. 

Then I started messing around and found that I had "filter" enabled on VR 2 settings, show below:



As soon as I set it to "Just show error - Default", the trigger error messages became erratic, and not on the whole time. Also, I would only occasionally see an error on the trigger log!  It seems like a bug to me, when filtering is enabled, the car drove pretty well but it reported an error every secondary trigger event.  Now, I only see an error when quickly revving the engine right off idle, the rest of the time it seems fine.

Below is where I am now: Trigger errors when "blipping" the throttle suddenly off idle. Also low speed driveability problems

This image shows primary trigger dropping out when quickly revving off idle.  After 2500 RPM, trigger is rock solid it seems.





Note:  there is still a 500ohm resiter across the VR2.  Tomorrow after work I will remove it and see if the signal is OK when revving up.

Thanks!

[VEMS]

Please use rising for both primary and secondary trigger, this should not change timing but might be causing your trigger problems. The way the input circuit is designed on the VEMS (when using VR) the rising edge is synced to zero crossing of VR signal, while the falling is variable time after. Variable time is dependent on VR signal Vpp and Slope result -> phase shift with rpm (variable).

In review i missed the Filtering enabled, good catch. It should be disabled in your application (just show). Depending on when your camsync occurs this might show some false trigger errors BAD SECTRIG POS, these can be ignored for the time being, will be fixed in up coming firmware release.

Best regards, Dave

[Grant]

Darn, I forgot you told me to set to rising-rising, not falling-falling.  The thing is, I know the CAS works as falling edge in the OEM format so I confused myself!

Another interesting note, my guide through this whole install has been my friend Keith, aka Sly.  My understanding is that he had a hand in designing the V3 hardware.  He mentioned that he didn't think changing from falling or rising would make much of a difference as the LM chip conditions the signal anyways and only gives a logical output anyways.

I will switch from falling to rising tonight and will report back.  Thanks!

[VEMS]

Hi Grant,

The LM chip conditions the signal you are correct, but if you take a look at the LM1815 datasheet page 8, figure 18 you'll get an idea what i am referring too. When using both VR sensors it should be less of a problem but still, we recommend rising when using VR. Please pass Keith my greetings,

Regards, Dave

[Grant]

Hi Dave,

I spent a couple of hours tonight in the 42F weather trying to push forward with the project. 

I did indeed switch the triggering for both primary and secondary to RISING, but didn't see much of an effect.  However, since you mentioned there may be some problems with leaving the triggering on falling for VR, I continued my testing in this state. 

Since that didn't help much, I started messing with the number of teeth between the 0 tooth and trigger tooth setting.  It seemed to help if I leave it at 4 or 5 (with corresponding timing change to suit), and I did have to remove the dizzy several times to turn the gear to allow for the correct timing range (Distance between first tooth and TDC). 

The problem still remains that the car starts and revs up fine it seems, but on quick acceleration blips the trigger drops out, causing a hesitation and a report of a trigger error.  My main goal is to solve this issue so I can start mapping on a dyno and return the car to my customer.

Does it matter if a spark event happens near a secondary trigger event? I noticed in some of the logs the two were awfully close, which was another reason I was messing around with the 0 tooth and trigger tooth settings.

Keith's on a road trip right now but he suggested I pull a complete data log with me revving to try to get the symptoms to show them selves and ask here.

I also have some resistors I can try to pull the whole VR signal down in case noise is an issue.

Any input would be greatly appreciated =)

Thanks,
Grant

[VEMS]

Could you post a logfile (vemslog) of the engine running with trigger filtering disabled (show only) at idle and triggerlog files (the files iself not screenshot, one during cranking without ign fuse (no start) and one during idle) for review ?

This will help me to narrow it down,

Best regards, Dave

[Grant]

Hi Dave,

Here is the current config:

http://www.vems.hu/files/GrantHendricks/risingrisingcoldstart%20tuning.vemscfg

Here is a trigger log file:

http://www.vems.hu/files/GrantHendricks/v3.3_u008216-2013-12-02-22.38.58.triggerlog

I'm sorry, I missed the part where you asked me to get you a log file while cranking with w/o ignition. 

I just have a log of the car running, and trigger errors at 5K and above.  I'm glad I looked at the file, I didn't realize I was getting errors above 5!

http://www.vems.hu/files/GrantHendricks/v3.3_u008216-2013.12.04-23.17.58.vemslog

I'll get you a the requested log tomorrow night.  Sorry =(

Thanks,
Grant

[VEMS]

Hello Grant,

Thanks for uploading the files, no further log taking required. I have reviewed your current set of files.

The trigger error BAD_STRIG_POS can safely be ignored for simple trigger plus cam sync. It sometimes gives false reading based on position of initial sync and does not cause resync but inform only.

I do not see any errors in running that might cause missfire (from trigger standpoint). It is more likely the engine is misfiring because its just running very rich. Please start by tuning the low rpm/low load section before attempting any higher rpms and work your way up gradually. I suspect this will solve any misfire issues you might have.

Best regards, Dave