Spark issue

[greatsouthbaybob]

Hello all,
At low rpm there is a noise coming from the motor that sounds like an electircal arc ticking and tapping, I tightened one of the plug wires and it stopped for awhile but has now returned, the motor sounds as if it's about to cut out at this time as well. Does this sound like a bad plug wire or maybe a distributor issue? Motor is 2005 merc 3.0 litre. Also are plug wires plug wires? Could I just use one from an auto parts store?
Thank you

 

[lilmandavis]

Re: Spark issue

get a spray bottle full of water and spray the wires and cap. see if it changes.

 

[greatsouthbaybob]

Re: Spark issue

get a spray bottle full of water and spray the wires and cap. see if it changes.

Ok, what type of changes should I look for and what do these changes indicate?
Thanks

 

[lilmandavis]

Re: Spark issue

if it starts to miss then it needs a tuneup. as for plug wires, dont get the cheapest ones they sell.

 

[greatsouthbaybob]

Re: Spark issue

Wait till it's dark or look close in the light and you should be able to see an arc jumping a blue spark if you can hear it.
Look around the coil tower and distributor cap. A crack will cause the arcing.

Thanks Don

 

[cobra 3.0]

Re: Spark issue

Sounds like you may have pulled the wire out of it's connector inside the boot. A 2005 should not need new wires.

 

[greatsouthbaybob]

Re: Spark issue

Sounds like you may have pulled the wire out of it's connector inside the boot. A 2005 should not need new wires.

Thanks for your input, I agree, however the I purchased this boat about a month ago, the previous owner had the starboard motor repowered in 05, this is the one with the spark issue, I have no idea what parts were reused off the old motor.

 

[Don S]

Re: Spark issue

Wait till it's dark or look close in the light and you should be able to see an arc jumping a blue spark if you can hear it.
Look around the coil tower and distributor cap. A crack will cause the arcing.

You may have problems finding automotive wires for a 3.0L engine with and EST distributor since there is no such thing in the Automotive world. However, you may find it as an aftermarket marine product sold in auto parts stores under the Sierra brand.