1987 Porsche 944 2.5L

I recently got an oscilloscope and then discovered that it can be used to introspect ignition and other automotive issues. I have been reading and watching all I can find online. The car drives fine, but I only got the vehicle recently so I was very curious to see if I could spot any subtle problems using the scope. The scope is a Siglent SDS1104X-E.

Snap throttle before warming up:


I see a jump up in firing KV at snap throttle, and then this downward swooping of the secondary voltage. The primary voltage remains flat. All of the waves here are captured with my probe clamped between the coil and distributor.

After running the engine for a while, the swooping changes to a stepping shape:

I am wondering if that has something to do with the distributor/rotor making & breaking contact during that time, but only when warmed up.

I don't know what to make of these:
Voltage spike in the middle of the dwell period.
Whatever the nonsense is at the beginning of this capture
Is this a misfire? It's like it sparked, but the voltage is flat across.

Thank you for your time

The captures you have posted look text book in my opinion.
I don't do a lot of secondary analysis, it can be very subjective. But from what you posted, I see no issues. The large spike you noticed in the dwell area of one of the captures is most likely induced interference from the coil firing another cylinder.

Nice looking captures, looks like a decent scope.

Initially, I see no obvious issues. For giggles, you could short a plug wire or create an air gap to check your understanding. See how a genuine problem looks on the scope.

Like Noah said, I'm betting that spike in the dwell time is interference. A fuel injector might make sense, giving the timing (and if this thing has SFI, I really don't know).