Ford Falcon XR6 1998 EL.

This car seems very heavy on gas, when sitting at the lights the idle seems very rough.

The car stutters and rocks.

Have replace the Idle control solenoid, does seem to have any vac leaks.

Thinking it could be timing? or faulty map senser?

Any ideas?

Check your Map Sensor.

As SWC has said check MAP sensor or swap - and fuel pressure ie. standard =225kpa with vacuumn hose connected - 275kpa with vacuumn hose disconnected
xr6 =250kpa with vacuumn hose connected - 300kpa with vacuumn hose disconnected .
check inside vacuumn hose connection to regulator for fuel - caused by hole in regulator diaphram sucking fuel into manifold .

check for codes but remember that if any they may have been introduced by disconnecting things while checking for the problem ?