Hey guys, I always wanted to know... how does the ECM have the ability to change the timing in our older push rod and distributor engines? I always hear about people talking about how a knock sensor can retard timing to prevent a damaging knock... but how? I read the wikipedia article but I was wondering if someone can dumb it down for me hahaha. Thanks!

 

The distributor merely feeds information to the ecm on when to fire the coil. It is just a reference signal. The computer actually tells the coil when to fire.