Originally Posted by
Irving
I want to get one thing straight. My complaint has been in regard to excessive engine knock (pinging) since the ping fix was implemented. I have referred to this as "engine pinged it's head off out of the dealership". Instinctive, I knew that the ping fix had been botched. My battle has been to try and get the dealer to rectify this issue. Eventually, the pinging settled down (mostly gone). However, there was a certain roughness in addition to the mild PCS which left me with the sense that all was not well. This problem has now been resolved.
Below is an extract from the Haltech Interceptor manual:
Knock Control
Many factory ECUs employ knock control to prevent engine damage due to pinging. Generally the factory ECU will monitor pinging using the knock sensor and retard ignition timing to get rid of it. The problem with this for the Haltech Interceptor is that in the quest for more power, a tuner may advance the ignition timing, but this may cause pinging. The factory ECU then
retards the timing to get rid of the pinging, and the result is that the power curve becomes inconsistent and makes no more power. Haltech recommends that before applying advance, the tuner should retard the ignition timing to see if power is lost. If power is lost, then the advance can be gradually added until max power is reached. It is recommended that the tuner run the minimum advance that achieves the performance requirements. Haltech has found on several cars that maximum power was achieved with ignition retarded from the factory ignition curves, as the factory ECU was tuned to run on the verge of knock control all the time. Therefore more power was made by pulling the ignition advance back to a level that would prevent knock control operation and still make good power.
Now, let's look at the last two sentences carefully, in respect to the K24Z engine:
If the factory ECU is tuned to run on the verge of knock control all the time, this is probably done as a compromise between obtaining maximum power and maximum fuel economy. If the Ignition timing is retarded further, the pinging may be eliminated at the expense of power loss.
Any comments? Please feel free to add to this analysis.