Fuel injection has replaced the fuel delivery system on most new cars, due to its efficiency in delivering a precise amount of atomized fuel and air to the cylinder. The fuel injection system is composed of the fuel inlet line, the injection rail, the electrical connector and the fuel injector. A pintle cap sits on the bottom of the injector inside the cylinder. Pintle caps can become cracked or deformed and sometimes must be replaced. Replacing the pintle cap on the fuel injector requires the dismantling of the fuel rail system to reach the part.
Set the transmission selector in "Neutral" or "Park," depending on your transmission type. Apply the emergency brake and raise the hood. Refer to your owner's manual for the location of the fuel pump relay inside your main fuse box. It looks like a small black box and connects to the fuse block base with blade pins. Pull out the relay. Start the engine and let it run for two minutes, then shut it off; this will release fuel rail and line pressure.
Disconnect the negative terminal on the battery with a socket and wrench. Locate the screws or bolts that hold the fuel rail to the engine head. Use either a screwdriver or socket to remove the rail bolts, depending on the design. Don a pair of safety goggles to protect your eyes from any residual fuel left in the lines under pressure.
Rock the fuel rail back and forth gently while pulling up at the same time. Do not pull at extreme angles. The fuel injectors should release from the cylinder seats and pop out. Pull the fuel rail up and away from the head, as far as the electrical connector wires on the injectors will allow. If you have a hard fuel inlet line on the end of the fuel rail, use an end wrench to loosen the line nut and pull the fuel line free.
Turn the fuel rail up so you can see the bottom of the fuel injectors. You will see the small pintle cap on the end of the injector. Use a large flat-blade screwdriver to wedge between the pintle rim and the small rubber O-ring, but do it gently on all sides of the cap until the cap pops off. As an alternative removal technique, us a dental pick to remove the rubber O-ring, then place a thin-wall wrench between the pintle cap edge and the injector; wedge the wrench up and down to release the pintle cap.
Remove all pintle caps in the same fashion. If you have difficulty removing all of the injectors as a unit, disconnect the electrical connectors at the top of the fuel injectors, then disconnect the top of the fuel injector from the fuel rail by prying it free with a flat-blade screwdriver. Use a fuel injector puller to pull each full injector out of the cylinder, one at a time, and then remove the pintle caps individually.
