How do you adjust valves on a 85 Nissan pick up?

To adjust the valves on an '85 Nissan pickup, first ensure the engine is cold and then remove the valve cover. Rotate the engine to align the timing marks, setting the cylinder you’re adjusting at top dead center (TDC) on the compression stroke. Use a feeler gauge to measure the gap between the rocker arm and the valve stem; adjust as necessary by loosening the lock nut and turning the adjustment screw until the correct clearance is achieved. Repeat this for each valve, then reassemble everything and check the clearance again if necessary.