Back then, I wasn't interested in the actual "timing" of the calibration. I was running at an idle and just long enough to graph the optical pickup vs. the cam sensor high to low transition vs. the injection command. Obviously the injector command didn't change from one sensor to the next but there was a very slight change in cam position vs. crankshaft position and while I don't remember the actual values being that I did this 11+ years ago, the blue one was giving the PCM a later switching point for a given crankshaft position. I wasn't monitoring the high side either since the injectors are low-side switched; I didn't need to see all the flyback voltage from each injector on the high side.
Back to your question, the injector command on the scope was happening WAY before anything should have been happening based on the "windows" in the camshaft sprocket likely due to calculated injector latency. I never graphed FDCS at the same time although it only makes sense to assume that the commanded injection event sent to the IDM is based on the previous revolution's position data. However, seeing anything "odd" wouldn't have struck me as odd at the time since I wasn't really aiming to get actual timing values as I knew they weren't static (as you would like to see) and I wasn't interested in getting caught spending too much time with the dealership's optical pickup over the weekend. Mostly standard peak and hold appearance from what I remember but no time measurements were made so I have no actual timing numbers.
It's cool that you checked the CPS outputs vs actual mechanical crank movement but if you didn't ever actually watch outgoing timing while driving and comparing that to what you had asked for in your tuning software, why did you respond to my post like you had?
I'm not saying the maps you used then or now are wrong, or that you don't know what timing you're commanding, I'm just saying mine damn sure were wrong and I did NOT know what timing I was commanding even though before I scoped things I thought I did. Timing rose way, way faster than mapped, and the total values were way, way higher.
I haven't checked the recent templates I've gotten from Bill in the last few years but they seem a million times more accurate by ear.
But without ever scoping it I wouldn't have been able to calibrate my ear in the first place. And my gray truck with a carpet floor takes more timing for the same feel as the red truck with no carpet, lol.
As for the way the PCM handles real-time injection timing, the windows in the gear are offset ahead of the mechanical crank positions by a fixed number of degrees. Injection control is not handled on the previous rev, the fixed offset allows the event to be controlled real-time for the current event. I also struggled to figure out how you set advanced timing ahead of a trigger event. You offset the trigger. If you offset the trigger 90 degrees advance and you wanted 30 degrees of timing, you would wait 60 degrees worth of time after the trigger event was recorded.
John at Swamps showed me this on the full electronics mock up he had at home years and years ago where he had a cam gear spinning on an electric motor, pcm, idm and injectors all on a test board together, "running" while he could vary rpm with the electric motor and test actual live signalling and outputs. It was the first time I watched those signals on the scope.
It wasn't until I set my own scope in my seat that I was shocked at how F'ed the timing was compared to what I had expected.
On Edit:
On my DAC stuff, I did actually open a file with my old software and hacked up templates and again in the new software with new template and the maps I looked at looked very different! Exact same file. So something has definitely changed between what I used to use and what I'm using now in the template department.
