Unexplained Episodes of Stalling

Hello CorrectCraft Experts....I have a odd one for you that I can't solve and need your expertise. I have done my best to cruise existing topics as well as provide as much information as possible below. Thanks for taking a look!

Boat: 1989 Ski Nautique 2001, PCM 351. Electronic Ignition

Background: Purchased last October, I only took it out on the water twice, both without any issues. Over the winter it was winterized following best practices including an oil change, oil filter, etc.   Also during this time the fuel Filter housing was upgraded to a more modern one so filters were easier to find, etc.

Symptom: From a cold start, boat will turn over without issue, idle and level off as normal. I can cruise for 30-45 minutes without issue and this is usually about the time I make it to my destination so I dock it. Coming back 1-2 hours later (engine still warm), it will start fine, but then stall/die after about 45 seconds. After dying, I can usually start the boat right back, sometimes I have to wait a minute or 2. Apon turning back over, it will again run for about 30-45 seconds, then stall. This will continue 8-9 times until finally it decides to stay running and will be fine.

More Info on Scenario: The stalling happens regardless of idle, neutral revved, underway, etc. Two weeks ago I decided to replace the ignition coil. This seemed to have fixed the issue with an entire weekend without issue. That is until the last run of the day, when it stalled again, same scenario as above. After looking at it when the issue was happening, I noticed the ignition coil was unbelievably hot. So I did some reading, noticed that it said "external resistor required" on the coil and started tracing wires. I Found that the external ballast resistor had been bypassed. So I purchased a new ign. coil, and new ballast resistor and installed. Boat started an ran, but only had 1 hours to test. I am not confident this is a solution...

What I have Checked:
     I have attempted to follow the wiring system throughout the boat to ensure good connectivity an no major drops in voltage
     I have tested the battery with a load tester
     I have tested the alternator and confirmed a healthy 13.5-14 while engine on at the battery and throughout the system
     The boat has run 2 tanks of gas, so the gas that sat over the winter should be gone

What I have replaced:
     - Fuel Filter and Housing (as a part of wintirization last October)
     - Distributor Cap (likely unrelated, but it was time)
     - Battery (again, no issues with the other one, but a just eliminating items)
     - Dash Wiring (my local mechanic re-wired the dash switches so they all did not feed off the ignition)
     - Ignition Coil & Ballast Resistor (see "More Info on Scenario")

Side Notes: I have noticed that the volt meter on the dash never goes above 12.5 while engine is on. I have read this can be from corroded connections on the gages, etc. I am getting a ful 13.5 at the batter while engine running. This may/may not be related.

I greatly appreciate any thoughts/feedback on this one. I am stumped!

Thanks so much for the quick feedback and welcoming me to the Forum, I appreciate it.

I believe the EI conversion has been in place for several years (certainly does not mean it could not be causing issues)., I will ask the previous owner who I met and purchased this boat through CCFan about when that was done and if he had any issues.

Do you (or anyone) have any concerns about the 12.5 voltage on the dash or think I need to be look at the fuel system?

Again, thanks everyone for the feedback and help.

Thanks Tony for the input. I was able to clearly define that the coil requires an external resistor based on its specs. Initially, I thought it was coil releated so replaced it, but then this weekend it happend again, and only then I noticed that the resistor was not wired in, so replaced that and got another coil for good measure....

Agree on your response and thanks for the link. Do we think that issue of poor power to the dash is related to the stalling?   Regardless I will likely do the upgraded wiring to alleviate the 12.5v reading issue. Consensus on ignition coil being the culprit and replacing it, this time with a resistor, needs to be focus?   Appreciate the feedback everyone.

Thanks for reply. And excuse my lack of knowledge, the igniter module is the rotary that the distributor cap attaches too?

8122pbrainard wrote: The other potential is the EI conversions have been know to create problems. Unfortunately there isn't an easy way to test them. I'd switch back to a point set.

There are easy ways to check the EI modules with a Volt Ohm Meter. Just google your brand of EI and find the trouble shooting section. Just did my Mallory setup last week. It checked good and was a coil issue. Some on here are against EI conversions or EI in general. Seems odd to me that 99.999% of the auto and boat manufacturers would switch to inferior ignition systems. Thanks but I'll keep my Electronic Ignition in everything I own.

How is your coil mounted? If its mounted sideways than move it upright or get an epoxy filled coild like the msd blaster.
oil filled coils don't like to be mounted sideways. some run forever like that without issue but most do not.

Concur,
The EI was overstressed in an out-of-spec high current condition, and now fails under high ambient heat even if the coil's primary resistance was now corrected.

Its a toxic environment for electronics, high heat, high current (which was exceeded)   and suppressing the back-emf of a couple hundred volts from the coil, 200 times per second and more.

I understand it doesn't make sense at first.

With these boats fuel starvation is the typical diagnosis with stalling out under heavy load, but almost never occurs in neutral or low-flow conditions, it will manifest at highest speeds first. Your description was contrary to that, once it occurs after use, you said it can reoccur even in neutral.

If you still want to check your fuel system, make certain the tank vent is open, and the barb fitting on the tank outlet is clear of debris, those are the most common points of failure.

Consider electronix are unlike a fan belt or light bulb. They will fail in a myriad of ways, from entirely open or resistively shunted (easy) to more subtle and fail at certain temperatures, certain air gaps, conditions etc. and this is likely one of them...
You would not believe the processing that can occur on a two-wire part.

Failure analysis of mixed signal Hall effect sensors is my bread and butter. I diagnose similar and more complex automotive components, from ignition, crank sensors, proximity sensors, as well as stepper motor and LED display drivers, and find the point of failure to the sub-micron level when necessary.

I've seen how the sausage is made, and also know how it goes bad.

GottaSki, hear you loud and clear.

SNobsessed, I failed to take a picture, but I did write down "prestolite marine distributor sae-j1171" I know the sae # is genral, I could not read the exact model number very well. Its been in place for about 5-6 years, I believe.

If we are convinced this module needs to go despite the addition of a new coil and resistor, maybe I should buy a new one this week and have it on standby for the long weekend??

Again, appreciate all the expertise.

ah! I understand now, OK, will have to wait until the weekend when I can get some pictures, details. Thanks again everyone.

I have one I'll sell cheap

Jumping to conclusions,you don't even know what module is even in yours. If it is like Pauls go for it,but you gotta know first.

I would getting a new coil and module if I were you. Don't fool around with faulty electronics.

I also have a Prestolite EI module (purple wire). It was already on the boat when we bought it 15 years ago, too bad they are NLA.

Read the install directions and don't go bypassing the ballast resistor because someone once said so.