Fuel and exhaust systems – gasoline engines
Warning: Gasoline is extremely flammable, so take extra precautions when you work on any part of the fuel system. Don’t smoke or allow open flames or bare light bulbs near the work area, and don’t work in a garage where a gas-type appliance (such as a water heater or a clothes dryer) is present. Since gasoline is carcinogenic, wear fuel-resistant gloves when there’s a possibility of being exposed to fuel, and, if you spill any fuel on your skin, rinse it off immediately with soap and water. Mop up any spills immediately and do not store fuel-soaked rags where they could ignite. The fuel system is under constant pressure, so, if any fuel lines are to be disconnected, the fuel pressure in the system must be relieved first. When you perform any kind of work on the fuel system, wear safety glasses and have a Class B type fire extinguisher on hand.
All models covered by this manual are equipped with a sequential multi-port fuel injection system. This type of fuel injection system uses timed impulses to sequentially inject the fuel directly into the intake ports of each cylinder in the same sequence as the firing order. The Powertrain Control Module (PCM) controls the injectors. The PCM monitors various engine parameters and delivers the exact amount of fuel, in firing order sequence, into the intake ports. For more information about the fuel injection system, Fuel injection system – general information.
The fuel pump is located inside the fuel tank, and can be accessed by removing a locking ring on top of the tank. You must lower the fuel tank before you can remove this ring and pull the fuel pump out of the fuel tank. The fuel level sending unit is an integral component of the fuel pump and it must be accessed in the same manner.
There are two fuel filters. One is the nylon mesh fuel sock or strainer at the lower (inlet) end of the fuel pump/fuel level sending unit module, which is mounted in the roof of the fuel tank and protrudes down into the fuel inside. The main fuel filter is an integral part of the fuel pressure regulator, which is located on top of the fuel pump/fuel level sending unit module. No external fuel filters are used on any of the gasoline-powered vehicles covered by this manual. The fuel filters are extended-life parts and do not need to be replaced at scheduled maintenance intervals. They should only be replaced if diagnostic testing indicates the need to do so.
The exhaust system consists of the two exhaust manifolds, catalytic converters, exhaust pipes and mufflers. For further information regarding the catalytic converter, refer to Chapter Emissions and engine control systems.