Power Reduction Alarm Yanmar 6LY3

Was running fine then went over a wake from another boat, pulled back, then when I tried to throttle back up I got a "Power Reduction" alarm and could not get port motor over 1800 RPMs

Got back to dock. Changed all fuel filters and problem still persist.

Anyone experience this before?

Turbo? Injectors?

With electronic engines like the 6LY3 any anomaly that could damage the engine like an oil pressure drop triggers that alarm and reduces power significantly. But many times it is just a bad sensor or some other electrical glitch. I suspect the only way to troubleshoot it is with a trained Yanmar tech with the proper diagnostic equipment.


David

Hey David !
Hope you’re doing well

Was just reading up and going to put the display into diagnostic mode and see what comes up

Have a tech coming later

Thank you

Error Messg says Turbo Over Boost

Most 6LY series have a wastegate on turbo. Check that it is not stuck.

Or does it have a variable geometry turbine (VGT or VNT)?

Does your display show boost or charge air pressure? Get that showing on the screen and then power up both engines and compare.

yes it has a waste gate
I show boost on my digital screen

within the limits of what protect mode would allow as far as RPMs go, both motors showed similar values for boost and load.

I found th waste gate. Should I manual push it open? or hook up a pump to the tube coming form the air inflow side of the turbo?

how many lbs will usually open it?

alarm is supposed to reset when pressure drops below 29

I replaced fuel filters and ran her up yesterday.. Was fine unitl 2500rpms

looks like the gate in fact may be stuck

Gate was ok

I swapped the boost sensors from port to stbd to see if the problem followed the sensor and the fault never came back.

I suspect the sending sensor had a bad electrical contact and by discconecting and reconnecting it cleaned it up.

These are the same pressure sensors that are used for the oil pressure. A cpl months ago I was gettign very erratic readings from 55-over 100 and when I cleaned the contacts it read normal.

What probably happened was the sensor gave erratic hi values and kept throwing the cpu into protect mode. (above 29 psi will do this)

Seems to make sense. The joys of electronic engines...

Indeed
On the other hand , I’d rather clean the contacts than replaces turbo or worse

Thanks for your help

See you at the next glitch ?