****I have knowledge of programming but VERY little experience with electronics.****
I'm attempting to switch a MOSFET using a 3.3v signal from an Adafruit MCU module (Adafruit Module here). The load the MOSFET would be switching is a 3v water pump (Water Pump Info here). The MOSFET that was chosen is the PMV28UNEA from Mouser.com (MOSFET Datasheet here).
The problem I'm having is when the signal pin from the MCU is set to high, the MOSFET switches on but my multi-meter shows a voltage drop when the motor is connected. Without the motor connected the voltage is around 4v (expected from the battery). However, whenever I connect the motor, the voltage drops to around 2.30v and the motor will not cycle on. The motor did cycle on once when I first tried it but hasn't since. I can't figure out what's causing this drop in voltage. I've included a simple schematic along with the links to the MCU, pump, and MOSFET. If I'm missing any relevant information here that would help please let me know.