Sierra Cosworth 1986

Original Cosworth trigger system

8 crank trigger + 2 distributor triggers 90 degree apart (180 crank degree).

Set up triggers : primary trigger settings / configlet "lancia_cosworth"

Without the special lancia-cosworth trigger settings (as tried, according to original vemslogs) it won't work (because it has 2 cam pulses, not 1 as in the simple coiltype c008 trigger setup).

Problem 1:

Have to power down ECU 3-4 times before engine will start (ignition pulses does not appear in triggerlog).

Problem 2:

Seems that ECU must recieve 8 distributor pulses before ignition is enabled and the engine will fire up. So have to crank at least 6 sec before engine fires

VR scope signal primary+secondary trigger


Polarity good

When cranking it seems that the ECU must recieve 8 secondary triggers before ignition is enabled. This means that it must crank more that 6 seconds, before starting.

3 out of 4 times it will NOT start (no ignition pulses), even after 15 seconds of cranking and really good triggerlog with no errors at all.

When not starting the triggerlog looks exatly as the triggerlog below when cranking. All triggers are evently spaced and equal in length and time from 0 sec. to 15 sec into the triggerlog.

During the 0 to 15sec cranking there are no ignition pulses.

I have to power the ECU down and restart several times before ignition pulses appear in the triggerlog and the engine fires up right away.

Log starting and running

Hello Per,

I have reviewed the triggerlog and vemslog posted above and found the following:

Lancia Cosworth mode is not enabled in primary trigger setup dialog, perhaps you forgot to load the configlet "lancia_cosworth" ?

With correct settings (i have used your triggerlog above to generate a triggerwav for my bench setup to make sure it matches your on engine configuration) syncup and sparks is within one second.


Best regards, Dave

Also tested with some signal deviation: sectrig very close to primtrig (unlike the factory trigger which is almost midway), that also works well.


Now I enabled the Cosworth/Lancia bit and now I cannot start it at all. I have tried 7 times cranking for more than 10 sec. but no ignition pulses.


Now I got it started after trying nearly 10 times (lancia/cosworth configlet is still used)

Still it must crank over 6 seconds.

Still I have to start cranking up to 10 times before it starts


Hello Per,

I have reviewed your triggerlogs and vemslogs (test21-test22), there is still a misconfiguration present. Please adjust "secondary trigger settings -> ignore sectrig pulses above" to 255 (default value). I see this reset to default was not included in the configlet, i have adjusted the configlet so this is included in the future. Will be available though ini update in a bit.

Best regards, Dave.

That solved the problem. Now engine fires up after approx. 1-2 sec.

Thanks.... :-))