flood

Ok, so I read that the car has long term storeage for ECU settings that it has learned over time.

I am wondering if perhaps the knock sensor retards the timing when using a low octane fuel?

Would it be possible to reset the ECU (disconnect battery) so that it relearns all these settings using higher octane fuel? Bumping the timing in an engine can make a difference , even a tiny 1.6l. Since the ECU controls all the timing, maybe its long term says xnumber of degrees and doesn't vary much?

What do you all think?

EE_Chris

I've never heard of an 'ignition trim' parameter existing.

There definitely is Short Term and Long Term fuel trim parameters but not something that learns an ignition curve.

The knock sensor retards timing when it sense knock (duh) but if you try and use a low grade gas and expect that when knock occurs, the ECU 'learn' about it, its not the case.

shifty35

The only problem here is that the ECU will not advance timing more than the base ignition table will allow for. In order to see gains from higher octane fuel, you will have to advance the base ignition timing at the distributor. The ecu should retard when it senses knock, but I don't know how much I'd trust it.