A faulty fuel pump can cause poor engine performance and hard starting problems. When they fail completely you may be left with an engine that doesn't start. If you suspect your fuel pump has failed, you can confirm the fuel pump is received the correct voltage when commanded ON by the fuel pump control module using a digital volt ohm meter (DVOM). If the correct voltage is present, but pump does not activate, it is likely faulty. Use the DVOM in conjunction with a wiring diagram to determine the correct terminals for testing. You can access the fuel pump electrical connector and terminals under the rear seat cushion, below an access panel. On E90 models, a fuel pump control module is used in place on the fuel pump relay. The fuel pump module can be activated for testing using a BMW scan tool, if you do not have access to a BMW scan tool, attempting to start the vehicle will also activate the fuel pump control module, the module will send control voltage to the pump. Instead of seeing what we are used to, battery volts supplied to the fuel pump, we now see a voltage dependent on fuel supply demand from the DME. When testing, I usually see about 10 volts being sent to the fuel pump. In this tech article, I will go over how to test fuel pressure and volume. You will need an assistant to press the Start Stop button during the testing procedures.
Variations in pump design may also affect your choice of pumps to suit your particular requirements. Pump lubrication is accomplished by oil mist in the air flowing through the pump. Early pump designs experienced contamination problems and required constant cleaning and maintenance to prevent the pump vanes from sticking. Pump manufacturers like GZ Motorsports and Moroso have each addressed this in their own way so the end consumer can make a thoughtful choice based on his needs and interpretation of their individual pump features. Direct consultation with the manufacturer will ensure the best possible choice.
Changing an engine’s oil has always been a headache for most do it yourselfers. Just being able to access the drain plugs can be a major project. Then, you’re likely to have oil dripping on you, the engine and the shop floor, the driveway or on the grass. But now this all has changed. The patented LiquiVac Oil Change System vacuums the oil out through the dipstick tube, and turns your oil change nightmare into a dream. Just insert the hose into the dipstick tube, pump it up to create the powerful vacuum, then open the cap valve, and the LiquiVac’s vacuum action extracts the oil out the dipstick tube. It’s that easy!