Draining Gas from Cars

I believe the safety switch is designed to sense an accident where the vehicle is either on it's side or upside down. Of course ... you never know what you'll run into with a junker but if the car is sitting level the safety shouldn't be a factor in the mix.



Next time you go to start your vehicle turn the ignition to the run position but not the crank position. If you listen carefully you might be able to hear the humm of the fuel pump coming on. Once the fuel line at the rail has come up to the correct pressure it will cut out.

Originally Posted by Scrappah

I believe the safety switch is designed to sense an accident where the vehicle is either on it's side or upside down. Of course ... you never know what you'll run into with a junker but if the car is sitting level the safety shouldn't be a factor in the mix.

Next time you go to start your vehicle turn the ignition to the run position but not the crank position. If you listen carefully you might be able to hear the humm of the fuel pump coming on. Once the fuel line at the rail has come up to the correct pressure it will cut out.

That is only to prime the fuel lines. The pump will stop unless the computer [and or some other method] can tell if the engine is running.

Originally Posted by Immulmen

That is only to prime the fuel lines. The pump will stop unless the computer [and or some other method] can tell if the engine is running.

That's interesting. See .... i thought that there was a pressure sensor somewhere up around the fuel rail. I think you need something like 60 psi or above for fuel injection.

Once the pressure sensor hits it's pre-set it shuts the fuel pump off. If it's below the pre-set then the pump should be energized. Maybe there's more to it though.

I know there's another sensor that won't open up fuel from the rail unless the sensor unless it detects that the engine is turning.