Cummins 555 not starting when hot

[Jack McGrath]

This is the 2nd time in 18 months and over 1,000 miles. Twin Cummins 1989 VT555 - both times on short trips approx. 1.5 hours, both times we ran the generator at anchor for approx. 4 hours, both times starboard engine turned over fast but would not start, plenty of fuel - when engine cooled down it starts up just fine.

would a hot solenoid not open?

Usually our trips a several hours to another marina or anchorage and only sometimes run the generator to charge up the inverter batteries, always start right up in the morning

No recent work, fuel filters changed about 200 hours ago, fuel clean with no water visible.

Any thought would be appreciated, thanks Jack

 

[Island Cessna]

First thing I’d check is the shutdown solenoid valve. Sticking when hot, works when cool.

 

[jgwinks]

On my tour boat with it's DD's, the shut down solenoids sometimes stick and don't work. Same thing in reverse. A little spray lube does the trick.

 

[C lectric]

The shutdown valve is mounted on the PT pump. Quite small with a wire from your starting button/switch running to it. It is powered to open to run.
THey can goof up. Mine refused to shut the engine down after the PT pump had some work done. The valve likely simply needs some new seals and bits and pieces.

Should be available from Cummins as a kit.
Have your engine serial number handy, specific model number also.

 

[Jack McGrath]

Thank you all for the input, will try and see about rebuilding!

 

[Simi 60]

Our 855 Cummins with pt pump occasionally is hard to start ater a long run.
But if I give it a small amount of throttle and then hit the switch it fires straight up.