Rpm fluctuation then check engine

[djetok]

Tonight after being anchored for hours a quick run across the lake. The port engine started fluctuating rpms 7000 to 2000 to 7000. I throttled back slow down. The check engine light came on a minute after I came off plane and went into limp mode. Throttled port engine for a slight stream on pee holes. I shut it off and checked the cleanouts. I didnt push the plug down to see if it blew out. I just removed the ez locks and checked debris. Nothing there, so we went to the dock to put it on the trailer. While my buddy was getting the truck. I left the motors off and checked oil and felt around the impeller more. I started both motors to pull to the trailer and no cel and full thrust. Nothing looks out of sorts in the impeller or intake grates. I swapped plugs from port to starboard to see if it does it on the other motor tomorrow.

Cavitation or bad cleanouts (time for a rebuild)?

 

[Scottintexas]

I doubt the cleanout plugs had anything to do with it

I would guess debris or maybe some water in gas after sitting it settled and sucked up in the fuel pick up when you started back

 

[Scottintexas]

Did it go into limp mode becuase of overheat. Or some other reason?

 

[djetok]

Did it go into limp mode becuase of overheat. Or some other reason?

I am assuming overheat

 

[Scottintexas]

If it was an over heat i would suspect debris after being anchored

 

[swatski]

I agree with @Scottintexas, I have something similar happen after pulling a tube with lots of hard turns in a river - overheat and limp mode, then everything goes back to normal.

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[djetok]

I inspected the impeller, nothing there. I pulled the pump, nothing there. The air filter cover was loose is all. Checked all the connections, nothing. Checked oil yesterday and today. Smelled the oil for fuel, thought maybe a injector. What really bothers me is the rpms going up and down then check engine.

 

[Scottintexas]

Honestly I'd run it today and see if any symptoms return, I'm betting they won't

Debris in pump can do many odd things and while rpm fluctuations aren't the normal it's not impossible

I'm more concerned we dont know exactly why the engine light came on, you don't have a separate light for overheat?

 

[djetok]

Code 132 ... aps error. @Ridesteady

 

[djetok]

Meanwhile

We dont have a lot of internet @PEARCE said we wouldn't he was correct. Even with all the flooding we can see about 20 feet

 

[djetok]

So I unplugged and replugged the aps on both sides no issues. Ran perfect, it was running rich before, you could smell gas. So kept pulling the dipstick to check to make sure a injector was not stuck.

 

[Ridesteady]

Sorry to hear that, @djetok!

That's such an odd phenomenon that it's hard to know where to begin with troubleshooting.

Was there ever ERR that showed on the Ridesteady screen, that you saw? You can also check the history under SETTINGS -> SYSTEM INFO -> NODE STATUS.

Were you using speed control in GPS or RPM mode at the time? Or did you have it in OFF mode?

When did you order your Ridesteady? Were you a part of the throttle node recall to fix the VHF interference issue? Were you transmitting on VHF, by chance?

 

[Gym]

Are you getting full RPM at WOT? Is your acceleration smooth from idle to full power? If not it's possible you have dirty injectors. Possibly a can of Sea Foam will clean them. It's also possible you have a stuck injector. Are there any signs of water near your ECU boxes?

 

[djetok]

Sorry to hear that, @djetok!

That's such an odd phenomenon that it's hard to know where to begin with troubleshooting.

Was there ever ERR that showed on the Ridesteady screen, that you saw? You can also check the history under SETTINGS -> SYSTEM INFO -> NODE STATUS.

Were you using speed control in GPS or RPM mode at the time? Or did you have it in OFF mode?

When did you order your Ridesteady? Were you a part of the throttle node recall to fix the VHF interference issue? Were you transmitting on VHF, by chance?

Gps mode. I dont think it was ridesteady. It could have been a loose plug on the aps.

I was pretty early order, no vhf . The way it ran after, I unplugged and replugged. I am leaning toward a loose plug. I did turn the sync master off yesterday, with no change.

No error on ridesteady, I did look at the node and saw nothing. When I looked it was after I turned that engine off. It was one engine only. That leads me to believe it was maybe a loose connection. It was rough out there.

 

[djetok]

Are you getting full RPM at WOT? Is your acceleration smooth from idle to full power? If not it's possible you have dirty injectors. Possibly a can of Sea Foam will clean them. It's also possible you have a stuck injector. Are there any signs of water near your ECU boxes?

It was smooth the entire time, it just went up and down. The fuel smell could me being ultra aware. Both engines ran like they should. Hell it could be my aps for all I know. After I unplugged and plugged it back there were no issues. Up until I finally got the code to show , I thought it was over heat. These mr1 motors dont pee until you get above 3k rpm.

 

[Ridesteady]

Man, that is one curious issue! Most of the signals of the APS sensor are monitored by Ridesteady, and should show an error if they get out of range.

The smoothness of the fluctuation is also puzzling. Originally I thought perhaps a wire came loose, but the effects of that would likely be pretty immediate and would result in a check engine light pretty quickly.

If it happens again (hopefully it won't), see if you can take the cover off the throttle node and see if you see any water in there or anything out of order. Perhaps a gremlin got wet or something...

 

[djetok]

Man, that is one curious issue! Most of the signals of the APS sensor are monitored by Ridesteady, and should show an error if they get out of range.

The smoothness of the fluctuation is also puzzling. Originally I thought perhaps a wire came loose, but the effects of that would likely be pretty immediate and would result in a check engine light pretty quickly.

If it happens again (hopefully it won't), see if you can take the cover off the throttle node and see if you see any water in there or anything out of order. Perhaps a gremlin got wet or something...

Ok. My boat stays very dry. Maybe me just unplugging and replugging cleared it. Thanks for the help as always. @Ridesteady

 

[djetok]

Man, that is one curious issue! Most of the signals of the APS sensor are monitored by Ridesteady, and should show an error if they get out of range.

The smoothness of the fluctuation is also puzzling. Originally I thought perhaps a wire came loose, but the effects of that would likely be pretty immediate and would result in a check engine light pretty quickly.

If it happens again (hopefully it won't), see if you can take the cover off the throttle node and see if you see any water in there or anything out of order. Perhaps a gremlin got wet or something...

We were out all weekend with no issues since I removed the plug and reseated it. Maybe the installer didn't get it completely seated when I err the installer connected it and it just finally loosened up to interrupt signal.

 

[Ridesteady]

Thanks for the update, @djetok. Intermittent issues are hard to diagnose. Glad to know it didn't reoccur!