Rough Idle. 3.0L GL/SX 2009 (Red Engine)

Fleetwin

Lieutenant Junior Grade
Joined
Nov 23, 2011
Messages
1,141
Volvo Penta-3.0L GLP-J/SX Drive 2009 37 hours


All,

Series of events:

1. Last night, I got a wild hair and decided to look at the spark plugs. They all looked the same, sort of brown and clean. No rust or oily deposits.
2. Today, I decided to run the engine. Ran fine until it got warm. Then, a serious misfire at idle and eventually stalled.
3. I noticed a "snapping" noise in the engine compartment. Upon looking, I see spark jumping from the spark plug wire boots to the head on cylinders 1 & 2.

With that, I am finding it hard to believe that the wires are shot at 37 hours but I can be convinced.

My plan:

1. Replace plugs with OEM-MR43LTS (AC)
2. Replace Wires.
3. Replace Cap/Rotor

I will only use OEM Volvo Penta Parts.

I can only think that the misfires are due to plug spark jumping. All other speeds are smooth.

Ideas? Thoughts?


Am I on the right track? What else could cause this? My experience (automotive) tells me that arcing spark can definetely cause and idle issue.

I thought it may be the carburetor until I saw the spark issue.


Thanks.
 
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Fleetwin

Lieutenant Junior Grade
Joined
Nov 23, 2011
Messages
1,141
Re: Rough Idle. 3.0L GL/SX 2009 (Red Engine)

Parts Ordered from V-P.

Am I on the right track?


Another question:

I see no way to adjust idle mixture on the Holley carb. installed. Am I missing something?


Thanks.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,620
Re: Rough Idle. 3.0L GL/SX 2009 (Red Engine)

If the plugs are fouled for some reason, the spark tries to find the closest path to ground so probably not the spark plug wires fault. There has to be a spark somewhere.

Its the age of the spark plug wires and not the number of hours. I would have probably replaced them as well just to be safe though.
 
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dannys2004glastron175mx

Petty Officer 1st Class
Joined
Jan 15, 2014
Messages
307
Re: Rough Idle. 3.0L GL/SX 2009 (Red Engine)

yeah id say you are on the right track , I would replace the cap, rotor ,wires, plugs and fuel filter :)
 
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Fleetwin

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Joined
Nov 23, 2011
Messages
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Re: Rough Idle. 3.0L GL/SX 2009 (Red Engine)

Thanks all.

I have a 10 micron fuel/water seperator in line already. I'm pretty sure it's not that.

I just find it hard to believe that those wires went bad so quick. This boat is garage kept and run little.

I probably damaged something, removing the boots, when I went to look at the plugs.

As mentioned, parts on way!

Any other ideas-welcome!
 

Fleetwin

Lieutenant Junior Grade
Joined
Nov 23, 2011
Messages
1,141
Re: Rough Idle. 3.0L GL/SX 2009 (Red Engine)

Report back: Success!

Thanks to all the great folks here, she's back up and running right.

I would have never guessed that a simple "tune up" would fix her,

We tend to think the worst.

Replacing; plugs, cap, rotor and wires got it back in shape.

Who would have thought on a low time (37 hours) engine?

Thanks again-All.
 
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