Separating traffic

This is the situation: we have a host, ESX 3i 3.5 with 3 phisical nics. One for management, one for virtual machine traffic and one for iSCSI traffic.

We want to separate de traffic in diferent vlans, for example

VLAN1=192.168.1.x / mask 255.255.255.0 / gateway 192.168.1.1

VLAN2=192.168.2.x / mask 255.255.255.0 / gateway 192.168.2.1

VLAN3=192.168.3.x / mask 255.255.255.0 / gateway 192.168.3.1

so:

for vlan1, nic1 is in vswitch1, this is a vmkernel port group and the ip will be 192.168.1.2, gateway 192.168.1.1

for vlan2, nic2 is in vswitch2, this is a virtual machine port group and the ip range will be 192.168.2.x (for each vm)

for vlan3, nic3 will be in vswitch3, this should be a vmkernel port group (for ISCSI). The problem is this: for vlan3, the ip range is 192.168.3.x, so, we configure an ip in this range but the default gateway remains 192.168.1.1 (the one for vlan1). If we change de gatweay

Is this correct? How can we address this situation? What are we doing wrong?

Thanks