Misfires badly while idling (cold/warm start, or hot start)

Totally possible to have a partially restricted injector/s. Especially since it sits for a season. Getting more curious.

That?s what I am feeling as well. Any recommendations on cleaning the injectors?

Sorry. We clean a lot of port style injectors but have not cleaned DI yet. I have replaced a lot of #6 and #8 DI injectors on GEN5 GM though. Taking puddles at speed causes water to go up the firewall and force its way into the vertical cylinder where the injector is mounted. After boiling for long enough it penetrates the housing and shorts the thing out. Crazy how much fuel pressure they can keep inside but cannot keep water out. Not sure about Ford DI injectors but GM take 65 volts to open and 12 to control the ride back toward closure.

Interestingly enough, it was #4 on my Xsport that missed the most on cold mornings. Seems that the moisture from the intercooler rushes up the pipe and flows directly across the intake into #4. Swapping plugs around changed nothing. Swapping coils around changed nothing. Closing the gap to .28 helped some. Adjusting the cat warmup timing seemed to help the most.

Looking forward to finding out what resolves yours.

So by adjusting the cat warmup timing you mean increasing the timing for the CSER adder table? I think I originally did that 1 or 2 years ago that helped a bit with the weird lumpy idling in drive when after a cold start, you give it gas to move and have to stop right afterwards or nearby without really warming up the car fully. But what I noticed was the final spark advance is following an entirely different table altogether when fully warmed up. When it misfires, I will see it go from 5* to 30* and switches rapidly. The histogram looks like a saw tooth waveform. It should be relatively flat.

Yes. It was the CSER tables:
Adder 11545: In the top left, 15% throttle, 700F degrees, from 0 to 5 degrees advance
In the top left, 15% throttle, 800F degrees, from 3 to 7 degrees advance

Biggest difference came from the Base drive table 11535:
There was a big jump in timing (10 to 40) based on engine run time bet 150 seconds and 180. The rumble/mis seemed like it was on a schedule behaving exactly the same every time as the system allowed increased timing. I increased the lowest timing on the chart to 6 degrees and basically blended out. I am sure that I could have gone higher but I was very happy with the change.

Base Neutral 11539:
Same as Base

Attachment 107277

Here are my stock values. I've used modified values before but on the Base drive/neutral tables, I'm assuming 120 seconds has transpired because I'd let it idle for 10 minutes and the ECT would be around 170F. Which is where 40* advance is commanded for CSER.

Here are my other CSER settings Attachment 107278

Yeah, none of this can have any affect if it's been running 10 min.

I'd bet that you are right about it being injector related. Very curious what can be done for DI injectors.

So I've been paying closer attention to the misfires. During the cold start warmup where the ECT goes from ambient to 170F, Cyl 6 is the only one misfiring. Once it hits 170F, the RPM drops to 600 RPM and that's when Cyl 4 starts misfiring the most with 1, 2, 3, and 5 also misfiring a few times. 6 is pretty much quiet.