1. Locate the fuel filter. It is located on the passenger side of the engine compartment, near the firewall. It is a cylindrical-shaped object with two fuel lines connected to it.
2. Disconnect the fuel lines. There will be a hose clamp holding each line in place. Loosen the hose clamps and remove the hoses from the fuel filter. Be careful not to spill any fuel.
3. Remove the fuel filter. Once the fuel lines are disconnected, you can remove the fuel filter by unscrewing it from the fuel line fitting.
4. Install the new fuel filter. Screw the new fuel filter onto the fuel line fitting hand-tight. Then, use a wrench to tighten the filter until it is snug.
5. Reconnect the fuel lines. Slide the hoses back onto the fuel filter and tighten the hose clamps. Make sure the hose clamps are tight enough so that the hoses will not come off, but not too tight so that you damage the hoses.
6. Start the engine. Turn the key to the "ON" position and allow the fuel pump to run for a few seconds. This will fill the new fuel filter with fuel.
7. Check for leaks. Start the engine and check for any leaks around the fuel filter. If you see any leaks, tighten the hose clamps until the leaks stop.
That's it! You have now successfully changed the fuel filter on your 1990 Toyota 4 Runner.
