Exc 343 cutting out

[Woteva210]

hi
i used to be on planet nautique with another log in but have this issue so thought someone here might be able to help
boat is 2012 210 TE with exc 343 which I have owned since new
this just started after 280 hours. Goes fine for about an hour then just almost cuts out. Goes to idle but is running very rough for about 15 seconds( does not usually cut out/stop). It will then suddenly start idling perfect and goes good again for about 5-10 minutes. Usually happens when going approx 3200rpm for a while. It will then usually do the same 3-4 times.
So far we have checked fuel tank, removed gauze from bottom of pick up, removed non return ball valve in pick up, replaced LP fuel pump. I have blown back through fuel return line and pick line and both are clear & free. Am about to go out again to test.
If it happens again I will either replace the HP fuel pump or put gauge on fuel line to monitor fuel pressure if it happens
any thoughts most welcome. Thanks
forgot to say there is no error message on dash and dealer went out for 1.5 hours and it went perfect !!!!!

[oldsmobiledriver]

Sounds like the HP pump is getting hot. Go ahead and grab a fuel pressure tester before you go out. Sounds like the problem


If you mess with the King's Queen, you better watch your Ace Jack!
#Tomcat

[Woteva210]

Thanks oldsmobiledriver
im about to try a get that sorted now

[shag]

That sounds suspect of the HP fuel pump... It can't keep up with the fuel demand.

[Paxdad]

Sounds like a fuel issue but would also check ignition cap and rotor and spark plugs. That’s fairly low hours for the fuel pumps to be going bad.



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[shag]

Sounds like a fuel issue but would also check ignition cap and rotor and spark plugs. That’s fairly low hours for the fuel pumps to be going bad.



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Good point. I had a cap go bad once and you could not visually see anything wrong with it... New cap = solved the problem i was having at that time which I think was rough idling and a no start issue.

[charlesml3]

Good point. I had a cap go bad once and you could not visually see anything wrong with it... New cap = solved the problem i was having at that time which I think was rough idling and a no start issue.

Yep. Most likely that cap had a hairline crack in it. When it gets hot, the crack will open a tiny amount, and the spark will chase it. I used to work in a maintenance facility where we fixed forklifts. For some reason, they loved to crack the distributor caps.

By the way, if you do replace the cap, replace the rotor at the same time.

[Woteva210]

Now for the next instalment
drove boat to dealer after it all happened again and had to be towed back. Found that distributed cap and rotor were badly corroded. That must be it- all makes sense!! New distributor cap cap and rotor fitted. I drive 4.5 hours to dealer pick up boat and go for run near dealer with mate After 1 hour 10 minutes- just as we were getting hopeful it happens again. So bad again I don't think I will get back to ramp which is within sight. I call dealer who gets there immediately with computer.
We have it now we thought!! Well for next 2 hours it runs like a dream. Back on trailer and left at dealer. 4.5 hour drive home get there at midnight- what a great day
the dealer - Nautique Central- are amazing and they couldn't do any more
any more ideas welcome but this one is starting to hurt!

[scottb7]

ok, now i am confused. the dealer came there with the computer and still could not diagnose?

[Woteva210]

When it didn't go the dealer wasn't in the boat. Because the distributor cap was so corroded we all thought that was the issue. We called him when it played up and he came straight away but when he got in with the computer to diagnose the issue it went perfect for 2 hours- unbelievable !!

[Infinity]

Maybe a loose connection somewhere? Lots of places that could be left loose by mistake when replacing cap, rotor and wires. Boat could have bumped around and jarred something and when dealer hooked up computer, it was back in place, just an idea

[Woteva210]

Thanks infinity
we deliberately didn't touch or move anything as we didn't want to change anything
after it kept going we did move/play with some wires to try and make it happen but nothing
this one has everyone confused
we will just have to go out again with computer on it and hope it does it again

[Paxdad]

Replace the spark plugs and wires but get the plugs at Autozone etc much less expensive than dealer. AC/Delco iridium #41-993. You may have a parasitic plug wire.


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[Woteva210]

We believe the issue is resolved
Dealer was replacing plugs & leads next and noted slight rust marks on 2 plugs. Discovered manifolds were leaking water into cylinders. Replaced manifolds and did compression test etc-all perfect. went for run for 2 hours and all appears fine. Still to give a full day running but very confident that the issue is fixed.
Thanks for all the input & ideas- like most things it's a process of elimination (although very frustrating)


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