Mastervolt Whisper 6 Generator Fault

[Daz]

Hi,I am in desperate need of some advice in diagnosing a fault that has developed with the gen set.
Normally the unit gives a fault code if its shuts down due to a oil pressure, coolant temp,exhaust temp, over voltage etc.
The gen set runs perfectly for several minutes and then shuts down...no error,it seems that the hold circuit on the fuel solenoid is activated...just like it would when you hit the stop button on the remote control panel.
The gen set runs at 3000 rpm..there is no fault with fuel delivery.
The strange thing is that a few days ago I removed the fuel solenoid hold wire from the spade of the digital control unit,replaced it and it ran without fault up to this point..same issue again...runs for several minutes then suddenly shuts down.
I hotwired the hold circuit from the power supply to the fuel lift pump...same thing the unit shuts down after several minutes.
The hold circuit on the schematic is powered from the magneto=alternator of the gen set.
Could I possibly have a
1.faulty fuel hold solenoid,
2.faulty remote panel stop button
3.faulty Digital control unit.
Am I correct in assuming that a hot wired power source will continue to hold circuit.
If so some other issue is shutting the fuel solenoid down.
I can replicate all the sensor faults artificially,to give the fault warnings.
Thanks in advance

 

[gsholz]

It would have to be a tired fuel solenoid if you hot-wired it and it still releases after a few minutes.

 

[Gdavid]

All those are possibilities as well as a bad wiring connection in the safety system that is heating up due to high resistance as that connection gets too hot and causes too much resistance. I would figure out how to bypass it, keep track of the cylinder head temps with an infrared thermometer and see if it stays running, then you can add each sensor back into the loop until you find the fault.

 

[Daz]

All those are possibilities as well as a bad wiring connection in the safety system that is heating up due to high resistance as that connection gets too hot and causes too much resistance. I would figure out how to bypass it, keep track of the cylinder head temps with an infrared thermometer and see if it stays running, then you can add each sensor back into the loop until you find the fault.

Thanks Gdavid,notes taken,but would not the hotwired pull circuit over ride the sensors?

 

[Gdavid]

Thanks Gdavid,notes taken,but would not the hotwired pull circuit over ride the sensors?

I'm not familiar with your particular unit, but many are wired such that the fuel solenoid requires power to hold it in the run position, this electrical power is fed through a oil pressure sensor and temperature sensor, if either are outside of their allowed range, it opens the circuit and stops the fuel supply. If either sensor is faulty or there is a bad connection in the circuit, it will stop the generator. There is also the possibility that it is overheating and the temperature sensor is working as it should, a infrared temp sensor will tell you if this is the case. You shouldn't see any higher than 180 degrees on the cylinder head, if you do check your cooling circuit or for bubbles in your coolant (bad head gasket).