Help with simple Arduino/Transistor/Solenoid circuit
It looks like there are some issues with your circuit. Summing up the comments:


Your diode has the wrong polarity to stop back-emf
Your base resistor is too large


Here is an updated schematic with these fixes.







simulate this circuit &ndash; Schematic created using CircuitLab

You could also take a look at this answer to see a bit more info on driving a solenoid.