Manual - Chapter 5 - Fuel & Oil

2. Precautions to be observed when servicing the fuel system

Warning: Petrol (gasoline) is extremely flammable, particularly when in the form of vapour. Precautions must be taken. as described below, to prevent the risk of fire or explosion when working on any part of the fuel system. Note that gasoline vapour is heavier than air and will collect in poorly ventilated corners of buildings. Avoid getting gasoline in the eyes or mouth and try to avoid skin contact. In case of accidents flush the affected area immediately with copious quantities of water and seek prompt medical advice.

1. Always perform service procedures in a well-ventilated area to prevent the build-up of fumes.
2. Never work in a building containing a gas appliance with a pilot light or any other form of naked flame. Ensure that there are no naked light bulbs or any sources of flame or sparks nearby.
3. Do not smoke (or allow anyone else to smoke) while in the vicinity of petrol or of components containing petrol. Remember the possible present of petrol vapour from these sources and move well clear before smoking.
4. Check all electrical equipment belonging to the house, garage or workshop where work is being carried on (see the Safety First section of this manual). Remember that certain electrical appliances such as drills, cutters etc create sparks in the normal course of operation and must not be used near petrol or any component containing petrol. Again, remember the possible presence of petrol fumes before using electrical equipment.
5. Always mop up any spilt fuel and safely dispose of the shop towel or rag used.
6. Any stored petrol, or petrol that is drained off during servicing work, must be kept in sealed containers that are suitable for holding petrol and clearly marked as such; the containers themselves should be kept in a safe place. Note that this last point applies equally to the fueltank, if it is removed from the machine; also remember to keep its cap closed at all times.
7. Note that the fuel system consists of the fuel tank, with its cap and related vent hoses, the fuel pump and filters, the fuel feed and return hoses, the fuel rail. the pressure regulator, the injectors and any other related components. On US models, this includes the components of the Evaporative Emission Control System.
8. Most of the above components contain fuel under pressure in normal use; always relieve any residual pressure (Section 3), then wrap a shop towel or clean rag around the joint to prevent fuel spraying out whenever any component is disturbed, and wear suitable eye protection to prevent personal injury.
9. Before working on any part of the fuel system always switch off the ignition at the very least; preferably disconnect the battery (negative terminal first) to prevent the risk of sparks due to short circuits or to improperly-connected components. If test procedures require the use of electricity be careful to check all connections before starting work.
10. Read carefully the Safety First section of this manual before starting work.
11. Owners of machines used in the US, particularly in California, should note that their machines must comply at all times with Federal or State legislation governing the permissible levels of noise and of pollutants such as unburnt hydrocarbons, carbon monoxide etc that can be emitted by those machines. All vehicles offered for sale must comply with legislation in force at the date of manufacture and must not subsequently be altered in any way which will affect their emission of noise or of pollutants.
12. In practice this means that adjustments may not be made to any part of the fuel, ignition or exhaust systems by anyone who is not authorised or mechanically qualified to do so, or who does not have the tools, equipment and data necessary to properly carry out the task. Also if any part of these systems is to be renewed it must be replaced only by genuine BMW components or by components which are approved under the relevant legislation, and the machine must never be used with any part of these systems removed, modified or damaged. Owners must consult the local enforcement agency (CARB and/or EPA) for full details of local legal requirements before attempting any of the servicing procedures described in this Chapter or in the relevant Sections of Routine Maintenance - Major Service.

Next Section: 3: Relieving fuel system pressure