I need to set the timing on my 2002 nissan altima

Turn off the engine and connect a tachometer to the distributor per the manufacturer's instructions. Connect the timing light to the battery and then to the number one ignition wire. Start the engine and verify it's idling at 1,000 RPM. Adjust the idle speed if necessary

Point the timing light at the crankshaft pulley to determine the amount of adjustment needed. Adjust the timing by loosening the distributor mounting bolts and turning the distributor until the crankshaft timing mark lines up with the middle line of the timing light.