Quote:
Originally Posted by TonyS9
Would that not be less likely to generate a knock signal?
We don't know how it decides to generate the code. As you say a piezo crystal is hard to test with resistance. Maybe you could put a pulse in and look for a slighly delayed one back. Maybe you can feel or hear it in test mode, but its normally an input, it would need a strong output to do that so I doubt it. Maybe there is a low level noise signal from the engine running.
I have experienced it working with 95 and 12psi boost, you get a big flat spot.
In any case it hasn't come on again.
|
Higher octane fuel is much less likely to generate a knock signal, correct. The piezo in the sensor is tuned to resonate at the frequency produced by detonation/knocking (it's like a piezo-electric buzzer in reverse) and when detonation occurs, it will therefore produce a voltage spike. The ECU reads this as detonation and retards the ignition timing, reducing the power output.
Running it on 95 octane and 12psi boost is a good recipe to generate detonation so definitely worth upgrading your fuel to a decent super unleaded (97/98 octane) and particularly losing E10 and using E5 instead.