Depressurizing the Fuel System on an Aston Martin DB9

Aston Martin DB9 Fuel Charging SystemYou may need to depressurize the fuel system on your DB9 if you are going to do any work with the fuel rails or fuel injectors under the hood.  I am doing this as part of changing my coil packs and spark plugs, but you might be wanting to change a fuel injector or various other engine service tasks.  Normally the fuel system has ~40psi of fuel pressure (even when turned off as residual pressure), and if you are going to disconnect something with the fuel system under the hood (bonnet), you don’t want the risk of it spraying you, your car, or worst of all causing a fire.

Depressurizing it is fairly simple.  We are going to run the engine out of gas by removing a relay that operates the fuel pumps.  No fuel = no pressure.  Easy. Continue reading “Depressurizing the Fuel System on an Aston Martin DB9”