Mastervolt Whisper Ultra 6 won't start

[quandary]

I'd greatly appreciate advice from anyone who has had a similar problem.

Unit has been lightly used, about 100hrs but has stood for about a year. Keep getting "failure to start" on mastervolt control panel. Engine turns over but does not even try to fire when start sequence begins.
#have installed a new start battery... voltage drops from 12.7 to about 11.9V when cranking so its not a start battery problem.
#oil level is OK.
#have bled fuel and checked that there is no air in the system. Fuel is from main tank and main Volvo engine runs perfectly so not a fuel problem. Fuel lift pump is working fine.
#checked glow plugs (removed them to see if they heat) and cranked the engine with them out. Definitely fuel being injected into cylinders.
#checked visually fuel solenoid is energising by removing cover,
#checked exhaust temp, engine temp and oil pressure switches are all normally closed.
#disconnected air intake hose to make sure no air blockages.
#have not done a compression test because I cannot find what glowplug adaptor to use for the test. In any case if one cylinder had a problem, the others would try to fire?

So I give up! must be a quirk of these engines?

Could anyone suggest anything else to test for?
I'd greatly appreciate any advice.

[paulajayne]

Can you put another battery in parallel as crank speed may be too low.

[SO49]

Not sure it you're still looking for answers but after 9 years of living with a MasterVolt 8KW unit with 1000 hours I've been through a lot.

I would check the following:

Fuel - verify that fuel is actually being pumped into the high pressure pump. Remove the fuel line on the engine side of the fuel filter that's between the fuel pump and the engine and point the fuel filter into a cup. There should be a start button on the electronics box attached to the engine. Push it and the fuel pump will start pumping fuel. Make fuel is flowing out of the filter into the cup. And make sure it's diesel and not water.

On the high pressure side you should bleed the high pressure lines by loosening the connections at the injector and make sure there is no air trapped in the lines.

Compression - you will need to check this next. Why - because it it possible water has backed up into engine from the exhaust lift muffler and bent the valves. Happened to me due to a MasterVolt solenoid failure and the engine was toast (since it was Mastervolt's fault they did replace the generator.)

OK, so you've got compression, glow plugs working, and clean fuel going into the injectors - that baby should fire - could be others issues that will keep it from running properly but it should fire.

[quandary]

Thanks SO49
The problem turned out to be corroded valves caused by an exhaust loop that trapped some cooling water after shutdown. Pretty bad when one considers that it was very low run hours and was professionally installed!

[SO49]

I'm sure it was an expensive little fix - changing valves. We had a similar situation with our MV 8KW. It was professionally installed and the MasterVolt engineers at their office in Florida approved the installation plans because the generator was to be installed under a salon settee - and the whole thing was below the waterline.

However, during the first month we had an experience where the generator would not shutdown and began running at a very low speed - not enough to force water out the lift muffler. They also never told us how to shut down the engine in an emergency. So the impeller was pumping raw water in and the engine wasn't pushing any water out. So the lift muffler filled up and water come back into the exhaust and into the valves. The valves bent and I think the crankshaft also bent.

MasterVolt paid to replace the whole unit.