Alarms and Erratic Behaviour

[John Sukkar]

Hi team,

I was all geared up today for a boat camping couple of days with my kid and we got 5 mins into our trip and things just went south and we had to turn around. Spent the rest of the day troublehsooting issues.

Some background - Boat had been running fine and I decided to give it a tune up a couple of weeks ago. Plugs, wires, rotor and cap, oil, oil filter and CFM filter - all standard stuff I've done dozens of time. After that I took her out and after 15 mins of running nicely, got water pressure sensor fault. So I called it day, as I was just testing. I went home and changed the sensor (had a spare one) and fault was gone at idle and I packed up.

Today was the first time back out since. Started right up and got under way, after about 5 mins engine started cutting out every 4 - 5 seconds - no alarms. Idling in gear would stall, but idled fine in neutral. We were far enough out that I decided to drift and check a few things - reseated some plugs checking for corrosion etc. After that things got worse. It started doing a single beep every 5 seconds, wouldn't idle for more than a few seconds, started getting all sorts of alarms (TPS, PITOT, Lost Engine Com). I barely limped it back with alarms becoming erratic.

Now it will start but only idle for about 10 seconds before I get the beeping and it dies unless I give it some throttle. Under light throttle it will do the thing where it cuts out every few seconds. It was just doing that in gear before, but now it is also doing it in neutral.

I'm going to start tomorrow morning with checking all fuses, all grounds and terminals, clean and check all plugs on the engine harness and go from there. I don't have a scanner, but I have a Vesselview mobile arriving in the mail in a week or so if that helps. No alarms are thrown with ignition on but engine not running.

Does anyone have any ideas? Could it be a bad coil? What else should I be checking before I head to the mechanic?

Appreciate any help!

Cheers,
John

 

[scoflaw]

I'd put a new IAC valve on it for starters, sometimes they don't throw a code

 

[Flyer5]

If it was working fine before the maintenance, I would check around things that were changed or worked on before all else. Maybe and most likely it will be something that got changed or bumped.

 

[John Sukkar]

I'd put a new IAC valve on it for starters, sometimes they don't throw a code

Would an IAC valve affect it with an open throttle though? This issue started out while under load with throttle at least part way open. I'm no expert, but the behavior doesn't seem consistent with an IAC valve issue which openly really operates with a closed throttle.

 

[scoflaw]

If it does it when your into the throttle then no. Those dis. caps are problematic.

 

[John Sukkar]

I spent quality time down with the engine today. Here's what I found.

Does not stay clipped in and was barely seated. I zip tied it snugly together and all faults and alarms went away. I must have yanked on it somehow working down there in the past.

So annoyed that I didn't find that yesterday and cancelled our trip.

Probably not something anyone could have helped with or diagnosed without physically going through everything.

 

[Flyer5]

Glad you found it. As a former mechanic then industrial electrician, plus all out tinkerer. I found whenever you do something and there is a change for the worst. I always look at what you did and around what you did. Most times it was something you touched bumped moved or blew on that is the change for the negative.. Always do this before jumping in and changing parts and changing a whole bunch of things. Also it helps if you log everything you do for troubleshooting along the way. Analytical troubleshooting is a great course.

 

[Jimmy Buoy]

Strange that a loose connection there would create actual engine problems like stalling and missing. Isn't that the ECM's connection from the engine? If so, wouldn't it be sending information out of the engine computer to the Vessel View Mobile and possibly other instruments at the helm? Not sure why it would cause any physical problems with the engine even if unplugged.

I installed VVM on my boat last spring (works great) but previously nothing was attached to the ECM's connection from the engine.

Just curious if your physical issues resolved or just the alarms.

 

[Korkie]

Glad to hear you found it. I am with scoflaw, initially sounded like IAC. I think many of us carry a spare as when they go bad it is at the most inopportune time.
Kinda agree with Jimmy Buoy - shouldn't make a difference. Can only say that when we did our upgrade 2 years ago we were having all kinds of communication issues, beeps, alarms, engine momentarily shutting down and so on. Found the data cable coming from the stbd motor ECM had been completely severed and butt spliced. Replaced that cable and all the issues went away. Maybe just confused the ECM with having bad communication? Cannot explain it other than we chased that ghost for 4 seasons.