Purpose of the a K-Jetronic Surge Tank
Mk2 Sciroccos use a surge tank for Bosch K-Jetronic fuel systems. Both 8v & 16v vehicles. These surge tanks do a couple of things. First, the internal fuel pump, transfers fuel into this tank. then sends fuel to the external hi pressure fuel pump. Next the fuel pumped to the fuel distributor. Any excess fuel pressure that is left over returns to the surge tank. As a result, your engine will never run dry. The constant flow of fuel feeds the external fuel pump. This helps in heavy cornering situations and will never allow air to enter the fuel system. Any unused fuel not used by the external fuel pump will exit the Surge Tank. This will exit via the overflow port. This port returns the fuel to the main tank for a continuous closed loop system. This tank will also acts as a filter, if there are any large particulars present. There is also a one way valve the lets fuel back in the main tank if pressure builds up.
These tanks fit 84-1/2 and up Mk2 Sciroccos with Bosch K-Jetronic CIS fuel systems. / 14.5g / 55L fuel tanks. If you are replacing your fuel tank, you really need to replace your Mk2 Scirocco Surge Tanks. As you can see in the photos, this vehicle’s tank was extremely fuel soaked and almost to the point of failure. They should not be brown. This was because this fuel tank had very heavy corrosion in it. Furthermore, the fuel had been sitting in the tank for over 10 years and had never been maintained with fuel additives for long term storage. As a result, we had to replace almost everything on the fuel and EVAP system. So if you are replacing your fuel tank, you really need to replace this at the same time.