How to Change a Fuel Pump on a BMW E30

1. Prepare the vehicle for fuel system maintenance by removing the fuel pump fuse from the main fuse panel located in the engine compartment. The exact location of the fuse for each model varies and can be found within the owner's manual. Start the engine and wait for the engine to stall. Remove the key from the ignition and unscrew the fuel cap on the passenger's side of the vehicle. Now that the fuel system pressure has been relieved, disconnect the negative terminal of the battery using a 10 mm socket and place the battery cable aside.
2. Access the fuel pump cover in sedans and coupes by removing the rear seat's lower cushion, which is retained by two Phillips head screws that thread into the rear passenger's footwell. Wagon fuel pump covers can be accessed by lifting up and removing the luggage area carpeting.
3. Remove the fuel pump access cover by lifting upwards after unscrewing the five Phillips head screws around the edge of the plate. Disconnect both electrical connectors made visible by removing the access cover. Both connectors are separated by pressing a small plastic tang on one side of the connector while simultaneously pulling the connector ends apart.
4. Disconnect the fuel inlet and return lines from the pump housing, first by sliding the retaining clamps further down each hose using a pair of standard pliers. Clean up any spills and wrap each hose end with a clean rag to prevent the entry of foreign debris. Determine if the pump housing is secured to the tank with or without nuts. If nuts are present, loosen and remove all eight nuts with a 10 mm socket. Rotate the housing counterclockwise and lift up assemblies that incorporate no nuts. Pry open stubborn stuck assemblies with two flat head screwdrivers between the pump housing and fuel tank at the locking tangs.
5. Separate the fuel pump from the pump and level sender housing once it has been removed from the tank. Remove the two fuel pump electrical leads using a Phillips head screwdriver. Remove the fuel pump pressure hose by releasing the clamp with a pair of pliers. The pump can now be replaced and reassembled using the reverse of these instructions. Replace the gasket between the fuel pump housing and fuel pump if there are any signs of damage or if the gasket appears to be dried out. Inspect all fuel lines for damage and cracking, and replace as necessary.