Generator won't run

[Ryan Wright]

Short story: Genset won't run. It starts, then immediately shuts back
down. No load on it at all. When starting, throttle solenoid is
observed pulling back to start, but then releases fully and lets it
die. Oil pressure gauge shows 90psi (!). Gauge works - it goes all the
way up during starting, then drops to 90psi, then genset shuts down.
I'm assuming at this point it thinks something is wrong with the oil
and shuts itself off. If I manually hold the the throttle, it
continues running fine. Oil level is OK, just below the second mark on
the dip stick. I changed oil, filter, & both fuel filters maybe a few
dozen hours ago.

Help! What do I do next?!

'86 PT-40 8V92, Yanmar 12.5kw genset



Long story (or, how we got to here): I took the bus in to a local RV
dealership to have the hydraulics fixed. They found the problem, one
of the jacks is leaking - more on that in another email. I asked them
to start the generator and run it all day with the front A/C on full
to keep the bus cooled down - it's >105 degrees here during the day
right now. When I arrived to pick the bus up, the sales lady was
inside trying to start the generator over and over again. She says it
was running fine for several hours when one of her techs shut it down
because they thought it was left on by accident. (Tech didn't know I
wanted it to stay running to power the A/C). So she went back out to
restart it and it wouldn't start.

That's the story. It was working fine before I dropped it off and
their work had nothing to do with the generator, so they shouldn't
have touched it. They claim they didn't. I'm assuming at this point
something just failed and need any advice I can get.

-Ryan
'86 PT-40 8V92
Tri-Cities, WA