How quickly does the knock sensor and ECM respond to a knock, and then retard the timing, then start advancing the timing back?

Just wondering if it could feel like a surging/miss if there was a problem causing detonation.

 

The ECM can act on the KS input within four clocks of the processor - or about 250,000 times a second. The greatest delays in the system are the processing of the program logic and updating the output device tables, and the time it takes for the ECM to communicate back to the EST and begin retarding timing. It can all happen so fast that I'd doubt the engine would surge as a result.

Advancing the timing after a detonation event depends on the programming. There are attack and recovery rates programmed in the ECM for dealing with the detonation sensor and EST, and the time can vary. The amount of retard steps can also vary.

If you suspect a timing problem, try to take the KS out of the circuit and replace it with a resistor. Be careful not to induce knock, since the EST will not detect it or retard the timing as a result.

 

Thanx for the input.

What value resistor do I want to use?

100K 1/2 Watt? Or what?

Then I wire it between the wiring harness and ground right?

This will cause the ECM to not detect a knock and hold the timing at full advance all the time, correct?

Can a bad timing chain cause this system to run erratically due to the cam and dist. advancing and retarding from the slop in the timing chain?