help with PSPICE code. urgent!!

I am trying to create the circuit in the image attached
I wrote the following code:

*Fitzhugh Nagumo
I1 0 1 PULSE(0 0.5mA 1NS 1NS 1NS 1NS 2ms)
L1 0 2 30H
R1 1 2 7500ohm
R2 1 0 3174ohm
C1 1 0 16.67nF
G1 1 0 value={-0.000037037*(v(1)**3)+0.00002167*(v(1)**2)}
.tran 0 10ms
.probe
.end

my problem is G1 isn't responding properly (it's giving me 0Amp) (and I think that because of that, also L1 and R1 are not working either)

can someone please help me?? THIS IS URGENT!!!

I've replied on the AAC site.