2015 AR190 troubles

[aaron jansen]

I'm having a problem. Had injectors cleaned, new plugs, and oil change this past fall. This year it won't go above 6500 rpm in the water where it normally goes 7850 I think.
I pulled the impeller this evening hoping it was jacked up but it's not. Can't figure this out.

I let two people borrow it end of last year and each sucked up a wakeboard rope. Won't be doing that again, not sure if that somehow got the impeller off pitch.

It kicks up to 6000 RPM at full throttle and gets on plane but much less power than before and top speed of 30. Feel a slight weird feeling at low speed like drive shaft or prop is out of balance.

 

[tdonoughue]

Would be pretty rare for a rope to jack up the pitch on an impeller. Not impossible, I guess. I have heard of bent shafts from ropes, tho.

The weird feeling--is it cavitation? Is your intake smooth? Maybe the rope incidents ripped some silicone out of the cracks? That probably would cause higher rpm, but lower speed, tho, I would think...

 

[aaron jansen]

It just feels off balance. Hard to explain. The drive shaft looks straight enough, but maybe I should inspect further.

 

[JetboatDrvr]

You should feel a distinct high frequency vibration if it were out of line and at 6000RPM, I would think it would almost eat itself if it were too far out of true. Engines are simple..air, spark, fuel, and some compression. Your description sounds closer to a cylinder not firing properly.

 

[aaron jansen]

is there a way to test the coils that you know of?

 

[JetboatDrvr]

I don't know, but the plugs should tell all. Have you pulled them to take a look?

I'm just trying to rule out the simple first.

 

[aaron jansen]

yeah, new plugs and cleaned injectors. That is why i went to the coil.
I am going to pull the fuel pump this afternoon too and see what state that is in.

 

[Dean P]

yeah, new plugs and cleaned injectors. That is why i went to the coil.
I am going to pull the fuel pump this afternoon too and see what state that is in.

Bad gas? How old is you're gas? Could try 91 octane. Strange the engine won't go up to 7800rpms.

 

[aaron jansen]

gas is a few months old but never been a problem before, it had marine stabilizer in it. Then also put in marvel mystery oil in it this spring

 

[Dean P]

Have you done any engine mods? Ribbon delete?

 

[aaron jansen]

yeah, just ribbon delete

 

[Dean P]

Wow, when I did my ribbon delete it jumped right to 7800 and stayed there. How many hours do you have on the engine?

Does anybody know if the computer can put these engines in "safe mode"?

As previously stated, maybe a cylinder lost compression or spark plug bad wires. I'd also check the connection and make sure they're down all the way.

 

[aaron jansen]

i will check the connection, engine has 220 hrs.

 

[aaron jansen]

I tested the plugs and coil packs. When I unplug cylinder 1, nothing happens. Unplug any other and it stalls immediately.

I swapped the coils, and same result.

Found a bad injector connection. Replaced it by done a linemans splice and liquid electrical tape.

I did the same test as above and it still stalls.

Not really sure what to do now...

 

[tdonoughue]

Theory: cylinder 1 is not firing--that is why it feels out of balance. Also the reason why unplugging that pack has no effect. Pulling another cylinder is too few for the engine to run and it stalls.

Have you checked the conductors inside the plugs? Some are known to be bent and cause failures. Any corrosion in there? If not, sounds like your issue is somewhere before the coil. I would next check the connector to the ECU for the same corrosion or bent conductor in the connector.

 

[aaron jansen]

full disclosure, I swapped the harness out with a nissan 350z harness. They are essentially the same and fit perfect. That still could be the issue. I wonder if I need to try the nissan injector as well. It should be cheap enough to try, the harness was only $3 at advance.

 

[aaron jansen]

Confirmed compression.

Pulled plug and wire, started engine and didn't see spark from cylinder 1

Swapped plugs and issue is the same.

Looks to be a wiring issue with cylinder 1

Next step is to wait for Amazon to deliver multimeter to test wires.

Any other ideas?

 

[tdonoughue]

The 350z harness--is it only on cylinder 1 or on all the cylinders?

Any luck checking the plugs for corrosion or a bent conductor?

 

[aaron jansen]

350z on 1 only. All plugs are essentially new.

No signs of corrosion anywhere.

 

[tdonoughue]

Did the issue begin right after you replaced that harness? That may be the issue...