L2850 Fuel pump ?

[HiramL2850]

My L2850 suddenly started acting lie it was running out of fuel; I have
Topped the tank, cleaned fuel filter, opened purge valve. Runs, but rough, and seems to be starving for fuel. considering calling a shop,thinking fuel pump, but wondering if it's something else I could fix. Any ideas?

 

[North Idaho Wolfman]

Start at the fuel filter housing, pull it turn on fuel cock, if fuel runs good then install a new filter, cleaning a filter is never a good choice!
Then go to the lift pump and pull the input off check for good flow, reinstall then take off the output line, crank motor and check for slow pulsed flow, it doesn't move a lot of fuel, it's not like a fuel pump in a car.
If that looks good pull the injector lines off of the top of the injector pump and crank, should see slow small pulses of fuel out of each port on the pump.
If the looks good pull injectors and take them in to have them tested.