How to Change the Fuel Filter in a 1991-94 Mercury Capri
For those owning a 1991-94 Mercury Capri, changing the fuel filter is relatively easy and straight forward.
The manual recommends that the filters should be changed every 15-25,000 miles. If the filter is totally clogged, fuel will not pass through to the fuel injectors and the car will not run or not run very well. It might lead you to think that something is seriously wrong. The same applies if the fuel injectors become clogged.
Unlike many other fuel filters, this one is cased in metal and several inches tall and in diameter. It is quite big and is attached to the firewall behind the engine off center to the right. The Capri's use a pressurized fuel system and if you disconnect the hoses without depressurizing fuel will stream out.
The fuel system is even pressurized when the engine if not running, so to release the pressure from the system, do the following:
1. Start engine.
2. Disconnect the Fuel Pump Relay, which is a connector behind the dash in the center next to the car's PCM (control center).
3. Within a short time, the car will stall because of lack of fuel. Turn off engine.
4. Reconnect the Fuel Pump Relay connector.
Now, disconnect the hoses to the fuel filter, some fuel will come out, so either have a container or plug them.
5. Install your new Fuel Filter securely.
6. Prime your fuel system by grounding the Fuel Pump Test Pin connector using a wire from the connector pin to car body. Turn on your ignition for 10 seconds. The fuel pump will activate and create pressure.
7. Turn key off and remove ground.
8. Start the engine.
If you do not prime it, it will simply take much longer for the pressure in the fuel system to build up, but it eventually become normal again.