I am starting to wonder if Async as I have seen it described by GM training manuals is some what generic. What I have seen at this point, leads me to believe Async can be different things on different engines. Or maybe Async isn't allways the correct terminology for injector to DRP corolation changes. I have seen four cylinder TBI skip an injector pulse between DRP and go to Sync above idle or under load. Other four cylinder TBIs have idled at Sync and added an extra pulse between DRP during load. As the opportunities arise I will collect more patterns from other engines and post.
Is AE a combination of PW and more injection pulses? The scope is a Pico four channel. This scope has a trigger function that is used to correct screen jitter so the patterns are easy to evaluate. It can freeze patterns and enlarge them. It also contains a small buffer to save a string of patterns. When examining injector patterns this scope picks up pintel bump during the closing of the injector caused by the metal rod moving in the magnetic field.