The first circuit you had you were using the FET in a source-follower mode, so the output will be the gate voltage minus the Vgs at the current it stabilises at. It isn't a logic level FET, so a higher voltage on the gate will help greatly in getting it going. As it is the drive is marginal.
Your last circuit is the typical setup for an N-channel FET. It is used as a switch to ground, based on a high voltage on the gate. If you are still using only 5V for the gate it will not be turned fully on, but will possibly do the job.
If you change to a FET that quote a Vgsth (turn on threshold) of of 3 or 4V or less it is a "logic level FET" and will be slammed on solidly.
One word of caution if you happen to use source-followers again (this is to anyone who is listening!). They can oscillate if the situation is right, even though the nominal gain is less than one. A capacitor from gate to ground helps heaps usually, and a resistor in series with the gate I call mandatory. I have seen this on two occasions in 18 years. If the circuit was connected to an igniter it could have led to "exciting times".