This is 1990 ASDZ Bin. First is idle. Second is power braking.
Red = Reference
Blue = EST
Green = Injector
Yellow = Injector
This is 1990 ASDZ Bin. First is idle. Second is power braking.
Red = Reference
Blue = EST
Green = Injector
Yellow = Injector
Nice! Looks like Sync at idle and Async during power brake? I wonder if the power brake cause AE or some Async condition? When I datalog the AE or Asycn flag hardly ever comes on, only WOT high load. Not off idle...
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
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It would be interesting to see what happens when the AE and Async flag comes on. The vehicle I tested with is not road wothy or I would do the WOT road test. I have seen Inj pulse added between the DRP on S-10. Now I wonder if there are three modes of injection. Every other DRP, every DRP, and every DRP +one in between during AE - Async? When weather gets better I will check my 94 GMC on the highway. It's amazing how one question and answer leads to another question. I guess that is why we like this stuff.
I thought the AE was added to a pulsewidth? Those scope graphs clearly show Sync idle and Async off idle, right? What I was saying is now no Async flag shows up all all except VERY high load, way beyond when AE would have been enabled. There is no AE flag in $42
I'll have to compare ASDZ which is CA version of ASDU Fed version for any changes.
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
AE is added between injectors referenced to DRP. I've seen this on the '7730 for sure, possibly the '7747 as well.
POZE what are you using for a scope to get 4 traces?
The man who says something is impossible, is usually interrupted by the man doing it.
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.
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