Technologies changes over time. Whenever you worked on your car and replaced the Fuel Filter. If it wasn’t an intank Fuel Filter, one of the problems you used to encounter was that your car wouldn’t start due to an Airlock in the system.
The DIY method to fix this would be to prefill the filter pot with a supply of fuel, and then starting the car. Using a vacuum bleeder or cycling the fuel pump with the ignition key a few times. Cycling the key used to prime the pump which pushed fuel through. The reason people did this is because it gives your car enough fuel to start. This then normally gives the car time to pull through fuel from the fuel tank, and returning fuel back into the tank (essentially giving the car time to bleed out the air). If you didn’t do this, it used to be a pain in the arse and sometimes the car wouldn’t start and you’d have to troubleshoot it
Modern cars are still the same, although because Technologies have improved over time. If you own a VAG based car, you can utilise the Software features of VCDS to do this task for you in order to prevent the car from stalling and starting first time. This procedure cycles the Electronics to the fuel pump which pushes fuel through the system. This then refills the chamber for the fuel filter and sends it back to the tank.
You can also use this procedure if you have replaced the Fuel Injectors or Flushed the Fuel from the system (perhaps if wrong fuel used). By doing this, it just makes the process easier. No messing around with pre-filling, or using a vaccum bleeder. Just press a button, wait and start the car
If you have never done this before, it’s a really simple procedure when using VCDS. I’ve listed it below
PROCEDURE TO PRIME THE FUEL PUMP
- Connect the VCDS Diagnostic Cable to the car
- Open up the VCDS Software
- Click on Group 01 – ENGINE
- Click on Menu 04 – Basic Settings
- Click on the Drop Down Options – Choos the option FUEL PUMP SUPPLY ACTIVATION
- Click ON/OFF
- Wait about 30 secs, you will hear the fuel pump priming, and a glow plug light will flash on this dash
- Once this is finished click DONE – GO BACK (If you’ve replaced injectors, or flush fuel, do this 2/3 times)
- You should now be able to start the car.
- You can then exit the software
I’ve also created a Youtube video for this process. Please feel to free to share it if it helped you out