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Interesting issue regarding 3SGTE and COP ignition


Felix Kreysig

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I just dropped my distributor ignition in favour of four 1ZZFE coils. After I wired and triple-checked the 4 IGN outputs to the corresponding coils (no. 1 being the coil at the cam wheels as it is common practice) and tried to run the engine: nothing. Not even the slightest hickup... so I once again checked spark, fuel, timing and found everything to be in order. 2 hours of kicking cans, yelling at the car and sitting in the corner crying I made a last attempt to solve the issue and wired in the channels at a 360° crank angle displaced order i. e. the ignition order was now 4 2 1 3 instead of 1 3 4 2 (yes... I could have done that via software... argh) and.... RUNS.

So whats the point? Does the Link ECU use inversed cylinder numbering starting at the flywheel instead of the cam gear side? Sequential ignition worked fine since first startup, so I think I can exclude any wiring mismatch.

Just FIY: the 3S cam position sensor uses two pickups which are seperated by 360° crank angle, so if you wire in the wrong sensor, everything will be displaced by 360°...

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the correct answer here is to put everything back as 1 to 1 etc then adjust your timing offset this will correct the issue 

check that the injectors are indeed firing 1 as 1 ,2 as 2 etc because if the timing reference is incorrect then the injectors will not be firing at the correct time either so you will not be getting the benefits of sequential injection

Regards

David Heerdegen

[email protected]

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The engine ran great with distributor setup, pulled 368 flywheel horsepower at 18psi with a BorgWarner EFR 6857, had better than stock cold start habits (I love the pre-start injection feature), stable afr even without closed loop control. Since  swapping to COPs and doing some cylinder selective fuel / ignition tuning fuel economy has improved beyond stock as well, so I assume injector and spark timing are correct (I once messed up wiring with an AEM FIC and injecting fuel while intake valves are closed produced some interesting black clouds, misfires and so on...)

Is there any means of checking the firing order of the injectors in correspondence to the spark timing via datalogging?

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yep  no different than group fire or semi sequential

ignition should ALWAYS be 1 to 1 etc  if this is wrong then the injectors will be firing wrong

never guess  test all you have to do is a test injector function and confirm that the right injectors are clicking when activated

Regards

David Heerdegen

[email protected]

 

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  • 2 weeks later...

Little update:

Moving the offset to 360° did not work, as the software rejected any changes in that numerical size. I the decided to switch the G1 / G2 (i.e. cam position) sensors which lay 360° apart and voilá! Works as intended. IGN 1 fires as 1, INJ 1 as 1 and so on.

The injection indeed must have fired 360° displaced as well, as increasing accel enrichment never helped getting rid of sudden acceleration hesitation. Now it works beautyfully.

 

Thanks for the input, Merry Christmas

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