ZD28 engine shuddering

[pgmitchll]

My mower has started to shudder at unexpected times. I have to stop mowing and allow the motor to get over its fit. Lately it just won't stop it. I have changed the fuel filters and pump. I have back blown the fuel line just in case there is debris blocking the intake from the tank. Nothing helps. Sometimes it starts right away and sometimes I can get partial mowing done then it's "all over" cause it won't stop.

 

[whitetiger]

Remove the fuel hose at the injection pump and hold it over a catch can or bucket, turn the key switch to Run. See how much fuel is being pumped out of the hose. It should be a full stream that pulses because of the electric lift pump.

If it just trickles you have a restriction in the tank, filters, hose, failing pump or plugged vent in the fuel fill cap. Loosen the cap and see if there is any change. If it is weak, remove the fuel cap and place a rag over the opening, remove the supply hose to the first fuel filter and blow thru it into the tank with a burst of compressed air.

Now put the hose back on the first filter and check the flow into the catch can again. If you have a good flow, remove and clean the fuel tank.

If you still have a weak flow, change the fuel filters and check your hoses. It is almost always debris in the tank and/or plugged lower fuel filter.