Spark plugs & Fault code help

[Amad3]

I purchased a new 2017 HO Impulse two years ago. I put the boat in two weeks ago and put in 6hours when my check engine light came on. My boat now has 75hours and I'm getting P0300 and P0301 codes... I'm guessing I need to change the spark plugs? Is there a diy to show where the spark plugs is and what NGK plug I need to order?

I'd take it to my dealer, but it'll be two weeks for them to look at it.

Any help or advice would be great!

 

[Luc Lafreniere]

Yeah, typically that's either bad plugs, bad gas or dirty injectors. I'd start with the plugs for sure... simple and easy to do (and low cost). Spark plugs: NGK DCPR8E.

On the top of the engine is a plastic cover. You simply pull that up and out (it just snaps in place). You'll then be able to see the three ignition coils. Just pull them straight up to get them out. Then use your socket with extension and proper plug socket to get the plugs out. Use the ignition coils to grab and pull them out. Inspect them, put new ones one (ideally) and hand tighten them until fully threaded. Then do 1/4 turn, NO MORE. Or if you have a torque wrench, 13 lbf.ft. Get some dielectric grease and slather it at the top of the coils to make sure no water can get into those cylinders. Also, be very careful with particles getting into the engine. Keep a clean rag over top of the holes while working. Don't get debris in there.

After doing all this, test it out and see if the codes clear. Hopefully you'll notice the condition of the plug(s) and that will be a good indicator that this was the problem.

Alternatively, how old is the gas in there?

 

[Dean P]

It's not necessarily the plugs (which should be changed out every season). What's the condition of your battery(s). Weak bats can cause several things to happen. I'll get these codes if I've been out all day trying to start the engine on just the 1 battery.

 

[Luc Lafreniere]

Definitely check your battery as Dean is saying. He's very correct. Odd codes when batteries are weak...

 

[Amad3]

Alternatively, how old is the gas in there?

So there's 3 spark plugs to replace? I'll order them today.

I just bought the rec gas, put in 10 gallons and took it for a spin. Then an hour later, the light went on. I'm thinking it might be bad gas.. But I'm also thinking it's time for new sparks plugs since I'm at 75hours.

 

[Amad3]

It's not necessarily the plugs (which should be changed out every season). What's the condition of your battery(s). Weak bats can cause several things to happen. I'll get these codes if I've been out all day trying to start the engine on just the 1 battery.

View attachment 120504

I only have one battery... I haven't replaced the battery since I bought the boat new summer of 2017... I can check the charge of it...

 

[Luc Lafreniere]

Yes, 3 plugs per engine. Definitely consider the gas... it's a possibility. I would just take the plugs out and inspect them while you wait on new ones. In case it's obvious. If they look clean and no issues, it's unlikely it's the plugs, but yeah, worth changing.

I would check your battery... make sure it has good voltage (12.8V at rest.. 12.7 is ok too). I'm on my original battery from 2016 and it's holding a charge perfectly and working well. But I do have a battery maintainer on it in the winter and recently added a cheap solar trickle charger as well while I leave the boat outside.

 

[Rick215HO]

I purchased a new 2017 HO Impulse two years ago. I put the boat in two weeks ago and put in 6hours when my check engine light came on. My boat now has 75hours and I'm getting P0300 and P0301 codes... I'm guessing I need to change the spark plugs? Is there a diy to show where the spark plugs is and what NGK plug I need to order?

I'd take it to my dealer, but it'll be two weeks for them to look at it.

Any help or advice would be great!

I just had exactly the same thing happen on one engine. So watching with interest.
I changed the plugs and coils and has been ok so far the last 4 hours. In addition to what has been mentioned here (if you haven't used the boat much) you could have condensation from the intercooler getting into the engine causing misfire, or bad coil. Interestingly enough my problem was also on cylinder #2. Check the conditions of the plugs (color / dry/wet when you pull them out.)

 

[Amad3]

I just had exactly the same thing happen on one engine. So watching with interest.
I changed the plugs and coils and has been ok so far the last 4 hours. In addition to what has been mentioned here (if you haven't used the boat much) you could have condensation from the intercooler getting into the engine causing misfire, or bad coil. Interestingly enough my problem was also on cylinder #2. Check the conditions of the plugs (color / dry/wet when you pull them out.)

When you changed the sparks and coil, how long did it take for the check engine light to disappear? Did it turn off right away? Or did

 

[Rick215HO]

When you changed the sparks and coil, how long did it take for the check engine light to disappear? Did it turn off right away? Or did

I reset it. Hasn't come back on.
I use candoopro.com to reset it.

 

[Amad3]

Yes, 3 plugs per engine. Definitely consider the gas... it's a possibility. I would just take the plugs out and inspect them while you wait on new ones. In case it's obvious. If they look clean and no issues, it's unlikely it's the plugs, but yeah, worth changing.

I would check your battery... make sure it has good voltage (12.8V at rest.. 12.7 is ok too). I'm on my original battery from 2016 and it's holding a charge perfectly and working well. But I do have a battery maintainer on it in the winter and recently added a cheap solar trickle charger as well while I leave the boat outside.

So I finally got back to my boat. I changed the spark plugs. The old ones look like they've the regular wear and doesn't look bad. The battery is at 12.7V when the boat isn't running and 14.4V when it's running... The check engine light is still on but I don't see the code option anymore when I scroll thru the mode button. I drove it around for a little bit but the check engine light didn't turn off. It seems to be running normal. Tomorrow, I'm thinking of filling it with more gas and also unplugging the battery in hopes to turn off the check engine light. And if it pops back up, then I'll take it to the dealer...

What do you think or advice?

 

[Luc Lafreniere]

I suspect you'll need the software or a dealer to clear the light assuming the problem went away. Battery voltage seems good at 12.7. Keep an eye on it from time to time. The voltage while running is normal since it's receiving a charge.

So hopefully the change in the spark plugs solved the problem (maybe the gap of the plugs? but who knows). If everything is running well after a while, then yeah, sounds like you just need the light cleared.

 

[Amad3]

I suspect you'll need the software or a dealer to clear the light assuming the problem went away. Battery voltage seems good at 12.7. Keep an eye on it from time to time. The voltage while running is normal since it's receiving a charge.

So hopefully the change in the spark plugs solved the problem (maybe the gap of the plugs? but who knows). If everything is running well after a while, then yeah, sounds like you just need the light cleared.

Is it common for the fault code to show then disappear?

I remember the first year I got it, the check engine light came on but I didn't see the fault code. It was also time for me.to take it in for the break in period. I asked about the check engine light and they said it was nothing.

 

[Luc Lafreniere]

Not sure, sorry. But yeah, it's entirely possible you're just due for maintenance, hence the light. Again, you'll need to get software or a dealer to check it out. I haven't bought it yet, but I believe the software is about 400 or 500 USD. In case it's of actual interest. If it avoids 2 weeks in the shop, may be worth it to you. lol

 

[Amad3]

Not sure, sorry. But yeah, it's entirely possible you're just due for maintenance, hence the light. Again, you'll need to get software or a dealer to check it out. I haven't bought it yet, but I believe the software is about 400 or 500 USD. In case it's of actual interest. If it avoids 2 weeks in the shop, may be worth it to you. lol

I talked to the dealership and they said changing the speak plugs should do the trick and the engine light should eventually go off. I took her for a ride and everything's fine, but when I get to about 12-13mph I can feel it misfire and the P0300 & P0301 code showed up again... So my only option left is bad gas. The tank is about 1/3 full. Is it better to fill up the tank with new gas or syphen the gas somehow and put new gas in? Or is there something I can put in the gas

 

[Amad3]

Not sure, sorry. But yeah, it's entirely possible you're just due for maintenance, hence the light. Again, you'll need to get software or a dealer to check it out. I haven't bought it yet, but I believe the software is about 400 or 500 USD. In case it's of actual interest. If it avoids 2 weeks in the shop, may be worth it to you. lol

I talked to the dealership and they said changing the speak plugs should do the trick and the engine light should eventually go off. I took her for a ride and everything's fine, but when I get to about 12-13mph I can feel it misfire and the P0300 & P0301 code showed up again... So my only option left is bad gas. The tank is about 1/3 full. Is it better to fill up the tank with new gas or syphen the gas somehow and put new gas in? Or is there something I can put in the gas

 

[Luc Lafreniere]

I would pull out as much as you can before adding fresh fuel. I'd try a simple siphon hose like this: Amazon.com: Safety Siphon - The Original Safe Multi-Purpose Self Priming Pump By The Original Safety Siphon - 6 Foot High Grade Hose, 1/2" Valve: Automotive Cheap and should work if the tube is long enough.

Keep the fuel because if that's not it either, then that fuel is good. After that, you're out of my league! lol Dirty injectors? Never accessed them. I know they sell additives to help clean them. Do they work? No idea.

Frustrating problem you have.

 

[Amad3]

I would pull out as much as you can before adding fresh fuel. I'd try a simple siphon hose like this: Amazon.com: Safety Siphon - The Original Safe Multi-Purpose Self Priming Pump By The Original Safety Siphon - 6 Foot High Grade Hose, 1/2" Valve: Automotive Cheap and should work if the tube is long enough.

Keep the fuel because if that's not it either, then that fuel is good. After that, you're out of my league! lol Dirty injectors? Never accessed them. I know they sell additives to help clean them. Do they work? No idea.

Frustrating problem you have.

I read somewhere to switch the coils and see if the code changes. If it does then the coil is bad.
And I just saw another thread on here where the guy had his fuel injectors clogged and used Techron Complete Fuel System Cleaner to clean it. I'm going to try those two out tomorrow. Hopefully that does the trick or I'll be taking it in the dealer next week.

 

[luanders]

any updates on this? having the same issue. P0300/P0301 - changed plugs, added fuel stabilizer, now onto coils and/or injectors i guess?

 

[JoeSpear]

Hey All, I was having the same issue with a pesky misfire that would not stop. I literally did everything possible to find the issue…..

 New plugs
 Swapped plugs from starboard to port
 cleaned injectors
 swapped injectors from starboard to port
 run lots of fuel cleaner through gas
 drained gas
 swapped gas supply lines from one fuel pump to the other
 swapped fuel rails from starboard to port
 Swapped coils from starboard to port
 swapped ECU from starboard to port
 swapped wiring harness from starboard to port
 installed new intake manifold gasket
 installed new O2 sensors
 checked engine compression

It was going on for about six months chasing this issue, and I just now solved the problem. My intercooler was leaking!

I swapped it out this weekend and just took it for a test drive, it works perfect now!!!!