Fuel pump with vapor vent

An electric motor fuel pump, comprising:

• a housing;
• an impeller having an array of a plurality of circumferentially spaced apart vanes rotatably carried in the housing, driven by the electric motor and having opposed sides and a periphery;
• a fuel pumping channel having an inlet into which fuel is drawn and an outlet through which fuel is discharged under pressure, the vanes of the impeller being at least in part disposed in the pumping channel;
• a first pump plate carried by the housing adjacent to one side of the impeller;
• a second pump plate having a face disposed adjacent to the opposite side of the impeller as the first pump plate, a groove formed in the face and defining in part the fuel pumping channel, the fuel pumping channel having a low pressure section extending from the inlet and a high pressure section extending from the low pressure section to the outlet, the low pressure section having a cross-sectional area larger than the cross-sectional area of the high pressure section, a vapor vent passage through the second pump plate having an inlet spaced radially inward from the groove and the fuel pumping channel and located immediately adjacent the transition of the low pressure section into the high pressure section, the vapor vent passage communicating with the exterior of the housing, and a connecting slot in the face communicating the groove with the inlet of the vapor vent passage to permit fuel vapor in the fuel pumping channel to escape therefrom through the vapor vent passage, the connecting slot opening directly into the groove and pumping channel immediately adjacent the transition of the low pressure section into the high pressure section and extending from the groove to the inlet of the vapor vent passage at an acute included angle to the groove and downstream relative to fuel flow through the groove and the pumping channel.