Why would my Honda prelude have no power to fuel pump?

Answer 1

Honda has a gas cut off switch, which cuts off your fuel if you are in an accident. Perhaps this switch is malfunctioning

My experience is that the detection of power to the fuel pump requires removal of the fuel pump connector and a multimeter to determine if voltage is present, at the connector, when the key is turned to the "on" (not "start") position. If no power is detected, the MASTER RELAY is suspect. Responsible for ensuring all fuel is shut down when the electrical energy to the fuel system ceases, the master relay can suffer from micro-cracks caused by repeated heating/cooling cycles on the miniature PC board. An easy and inexpensive fix is to remove the little PC board and reheat the solder points (use soldering iron) on the back of the board. Be careful not to overheat as you can damage the components. The resultant solder point should be shiny, not dull. If you overheat the solder joint it will become dull. This "hunt" for the lack of power to the fuel pump was a long and frustrating process when I had the problem. That master relay controls the fuel pump and the injectors so that when you turn off the ignition, the fuel pump and injectors are no longer allowed to operate. The fuel is pressurized behind the injectors by the fuel pump. You'll notice that the car will start better if you turn the ignition key to the "on" position for 3 seconds before turning the key to the "start". This allows the fuel pump to pressurize your fuel lines before igniting the engine.

My experience is that the detection of power to the fuel pump requires removal of the fuel pump connector and a multimeter to determine if voltage is present, at the connector, when the key is turned to the "on" (not "start") position. If no power is detected, the MASTER RELAY is suspect. Responsible for ensuring all fuel is shut down when the electrical energy to the fuel system ceases, the master relay can suffer from micro-cracks caused by repeated heating/cooling cycles on the miniature PC board. An easy and inexpensive fix is to remove the little PC board and reheat the solder points (use soldering iron) on the back of the board. Be careful not to overheat as you can damage the components. The resultant solder point should be shiny, not dull. If you overheat the solder joint it will become dull. This "hunt" for the lack of power to the fuel pump was a long and frustrating process when I had the problem. That master relay controls the fuel pump and the injectors so that when you turn off the ignition, the fuel pump and injectors are no longer allowed to operate. The fuel is pressurized behind the injectors by the fuel pump. You'll notice that the car will start better if you turn the ignition key to the "on" position for 3 seconds before turning the key to the "start". This allows the fuel pump to pressurize your fuel lines before igniting the engine.