white exhaust valves

ok this i have replaced the following things: 1 cam, 2 head, 3 hla's, 4 all bottom end bearings, 5 front seal, 6 ecu, 7 plugs wires and cap and no more tick now but still have white valves on new head and valves how or what is doing this? car runs any where from 160 deg to 250 deg. what is causing my valves to turn white? how do i tune my fuel-2-air so its right? (thinking i might have 2 much air not enough fuel) 2.2l gl is the engine any ideas?

You can't adjust the mixture is controlled by the computer. Most likely you have a vacuum leak making it run too lean. You could run some fuel injector cleaner through a tank of gas if you think the injectors might not be putting out enough fuel.