BMW Coupes and Sedans 1970-1988 Repair Guide

Relieving Fuel System Pressure


Anytime the fuel system is serviced, the generation of spilled fuel and fuel vapor expose the technician to possibility of flash fire or explosion. All work should be performed in a well ventilated area with easy access to a fire extinguisher. All spilled fuel must be removed immediately. Wear protective eyewear. Failure to observe these precautions may result in personal injury.

To relieve the pressure in the system, first find the fuel pump relay plug, located on the cowl, as specified in the applicable Electric Fuel Pump Pressure Checking procedure. Unplug the relay, leaving it in a safe position where the connections cannot ground. If necessary, tape the plug in place or tape over the connector prongs with electrical tape. Then, start the engine and operate it until it stalls. Crank the engine for 10 seconds after it stalls to remove any residual pressure.