For the OP and this one
Originally Posted by capcass
I have a 1980 Yanmar 2Gm installed on my 30ft sailboat. It runs fine at all rpms, except below 1100 when it stalls. I've changed the injectors, filters and bled the system withtout any remedy. The lift pump was replaced last year. Any suggestion as to what to check next (i.e injector pump timing, compression, valve adjustment, etc.) ? I am prepared to bring in a diesel mechanic, but would like to know that he is following the right diagnostic process rather that just changing parts. Any suggestion on what may be the most likely cause of this low idle stalling condition for this engine would be greatly appreciated.
Gary Cassidy, USCG Master
When the engine comes down to idle then anything causing load on the motor will stall it .
So if your Alternator is under load because its trying to charge your batteries that will cause it . If your water pump is building up pressure for some reason that might stall it. If the shaft into the gearbox is binding for any reason that will do it.Perhaps there is a problem moving the rocker gear or a valve bent . Whatever causes the load.
Have the idle set higher than recommended . Say set it at 1000 rpm to be sure . It does not use much more fuel at that speed than 750 rpm,and you will feel safer. Your motor is talking to you all the time . Its saying ¨I´m loaded up and having trouble here Boss¨