If you have a fouled plug the engine will revert excessively because of the large delay between firing cylinders. Can you attach your program and do you have any logs to post.

I am running the Holley crank trigger setup with a cam sensor and CNP. The setup I use is Custom = 60-2. Inductive delay = 60 usec. Timing offset is used to correct the timing difference between the actual engine timing and the holley efi timing. TDC tooth = 11. Sensor type = digital falling.

I run a custom cam sensor that uses a MSD sensor. My set up is a single pulse type= digital falling.

Output setup = DIS coil on plug x RPM y MAP and I enable the dwell table.

Dumb question but what is your voltage at idle?

BR,
I have not ruled out air leaks but everything is fresh and tight - Gaskets etc... I am used to seeing water dripping at the header flange if things are leaking there and ave not seen anything like that.

kvogt,
I have not closely looked at idle voltage but the times I have glanced at the gage and the digital display on the laptop, it was reading 14V+/-.
Definitely with you on the plug fouling but I am not sure if mis-fires are more related to excessive water on the plugs.
No data logs yet but I will try and attempt to attach the current GF I am using. May have to upgrade my membership?

Hardware wise it sounds as though we have very similar set-ups.
I feel like it is definitely in the settings. Reading the manuals (system ICF Configurations section), it indicated for GM 58x crank wheel and "factory Coils" to set the dwell at 3.5Ms. With the dwell table enabled, do you set any base value? They also mention magnetic filtering for the crank trigger sensor. I believe the Holley sensor is a Hall effect sensor. Is this anything you enabled? It would seem the Holley sensor ought to be plug-n-play but one more thing I will look at.

My next step will be to move to the Custom ignition type and follow your settings. I'll take my old-school timing light out to see if the spark events are making sense at cranking speeds.

One more question, did you use closed loop learning at all for Idle tuning? Where is your timing and TAFR below 1000RPM? I ask because I have considered disconnecting the water jumper to the Tail pipe (dump it overboard) for short periods at Idle to keep the O2 sensor from getting wet as well as a way to sort out the spark plug(s) getting wet causing mis-fires. Obviously very limited to keep things from getting too hot!

Really appreciate you-all sharing this info!

Where's Haxby now ?

Actually, Alex (Haxby) has been a great help on this project! I could not have got this far without him.
Assuming he is busy, away or tied up with something burning.

I have the dwell table activated and my dwell values range from 3ms to 4.5ms depending on boost and RPM. This will also be coil dependent and I run the ING1A coils.
The Holley crank trigger is hall effect. I use the custom 60-2 settings.

I manually tuned the idle and shoot for an AFR in the mid 13s for both in and out of gear. Even if you dump the water out of the exhaust you will probably get false lean readings from outside air getting sucked back into the exhaust. With my mufflers closed the reversion is much reduced.

A brief update:
I went through cam timing by pulling the valve covers and walking through the standard firing order - Confirmed 18436572
I have an ATI Damper with full 360 degree markings and verified spark timing is correct for all cylinders.
Set ignition configuration to Custom and enabled the Dwell table. Set all values to 3.5Ms. (I subsequently looked up spec.s on the coils and it looks like they would recommend 3Ms for N/A, non-high compression.)
Verified voltage to be 13.7V-14.0V at Idle
Adjusted throttle plates to get IAC to hover in and around 15%-20% (Ran TPS Auto-set with each adjustment)
Ran static idle tests and while the measured timing is within a couple degrees of command, for some reason the timing offsets entered did not seem to have 1 for 1 effect. Not sure if inductive delay has an impact but I varied that a bit and it seemed the base timing stayed closer to set timing at lower values. This was baffling to me and any thoughts on what would impact the timing offset from being a direct influence would be helpful. I left the inductive delay at 60 to match Kvogt' settings and verified steady set timing up through 3200 RPM.
I also threw another set of plugs in.
FYI have done many plug readings after running at higher loads and RPM and they look great although I am still running open loop,

I was able to get an improved and stable idle in the 800-900 RPM although still rather "lopey"
I ran a couple of tests to see if the O2 sensor was still getting wet (used the fouled O2 sensors I have) and while reversion seems to be improved, the sensor still got wet. I don't yet know if it is okay for sustained idling without moisture/water getting into the oil. Where I boat, there is a 1/4 mile of channel to get to open water. I should also mention that the water entry point is more like 10 inches aft of the O2 Sensor bung and I am running a Hardin Marine SST water pump which pumps a crap-load of water.

I had ordered the Innovative bung insulator but unfortunately it did not come until after working on the boat so I did not have the courage to load a new sensor (to run in closed loop learn) in without it. I am anxiously awaiting next weekend so I can run the same wet tests with the bung insulator (and old sensor) before risking a 3rd new sensor.
I am wanting to run the O2 sensor because it seems I need to have excessively high TAFR's (14.5-15.5) to keep it from burning excessively rich at speeds below 1000RPM. (loading up and smells super rich). I did one trial where I set the TAFR (in the idle zones for RPM and MAP) closer to 12.5 just to see if the poor idle could be due to a lack of fuel. Because we had trouble with the O2 sensor at the Dyno, I am thinking my base fuel table was never right down at Idle speed ranges.

Anyway, some progress especially with the feedback and experience. Much appreciate the help and will be back at it Saturday.

Cheers,
GT