Massive misfire cylinder 1 -- SOLVED (wire corrosion)

[Rkt Ship]

Often its the small stuff that gets overseen and gives you a hard time.

If you want to check if a valve isn't closed, you could pull out the injector and stick a litte USB endoscope down the injector hole.
On the other hand, if a valve is not closed, compression is gone. If it starts OK and suddenly don't run right, it doesn't look like an open valve.

It could be something simple, like a corroded plug/socket in a cable assembly inside, on the left side and below the dash. The wires from the ECU go from there via another plug/socket to the injectors.

That's a good idea to check. It's not a stuck valve though unless it's stick closed. When I opened up the valve cover I didn't have any broken or bent stuff up there.