MEP 003A Stalls/Hesitates while running

[dfullerpt]

I recently picked up a second MEP003A and prior to taking it up into the hills, I installed new filters, batteries, oil and fuel.

It fired right up and we test ran it for about an hour with a load of 15 amps on it. The unit functioned perfectly.

Now we brought it up to our cabin and after hooking everything up fired it up put a load on it and it was fine for about an hour. Then the engine began to stall and hesitate. I took the load off and the unit continued to do the same thing it would almost stall to the point the engine would die but catch itself and run back up to speed. Within a minute or so it would do it again, thinking it might be a fuel pressure issue I swapped out the fuel pumps from one unit to the other but the same problem. I even swapped out the filters still the same.

Any thoughts would be appreciated. I won't get a chance to play with it for a couple weeks but want to have a plan when we go back up.

Thanks
Dennis

 

[rosco]

Bump

 

[Carl_in_NH]

Restriction in a fuel line or the check-valve? There's lots of places in the fuel system for crud to hide besides the filters. I'd go through and check and clean each line and fitting from tank to IP. Could also be something in the tank blocking the fuel pickup as it floats around; I've had a big flake of debris in a tank do this before.

 

[derf]

Is the solenoid actuating or not when the stall occurs? Governor moving?
Remember, GL gens were DRMO'd for a reason. You may have found the reason your unit was auctioned.

It has an electrical shutdown that could be acting up. It can be triggered by low oil pressure, among other things. Watch the solenoid and see if it moves and causes the stall. The oil pressure switch may be faulty.

If the solenoid isn't moving then start looking at fuel supply. Fuel starvation or air in the fuel lines might cause stalling.

Also, consider why it might run for an hour and then stall. An hour might be how long it can run on the fuel in the filters. Maybe the fuel pump(s) are delivering when the unit starts but then failing while it is running.

Where do you set the switch once it starts up? Some gens have aux settings that try to draw fuel from an external source and some have "combat" settings. Check to see if the electric fuel pumps are energized when running. Check "Prime and Run Aux Fuel" vs. "Prime and Run" switch settings.

 

[Carl_in_NH]

Then the engine began to stall and hesitate. I took the load off and the unit continued to do the same thing it would almost stall to the point the engine would die but catch itself and run back up to speed.

Not likely a low oil pressure or high temperature shutdown if it's catching and coming back up to speed or continuing to try and run. You could disable those sensors easily and verify. Seems very unlikely this is a control system initiated shutdown. Always check to make certain the IP is being commanded to deliver fuel while this faltering is being observed, as you could have a mechanical fault causing the fuel metering to close down on the IP.

An hour would be pretty impressive run time for the fuel in the filter cans on this genset, even without a load. I suspect another fuel system fault in this case. I really lean toward crud in the fuel system as the cause, given this unit is just being put back into service after sitting.

 

[dfullerpt]

Thanks for the replies. My first thought was fuel issue although I did not have enough time to investigate past swapping pumps, tried the selector switch on both Aux. and Run for the pumps no effect.

Watched oil pressure and running at 40 PSI hot, disconnected the fuel line and ran pumps to see flow seemed OK. I think when we go back up I will drain out tank and check all fuel lines and check valves for. I will need to read up on the IP so I will know what to look for when its running. We wont be back up for a few weeks so making a check list

I truly appreciate all the help.

Dennis