Fuel Temperature Control Fuel temperature is controlled by a thermocouple (bimetal valve. If the returning fuel is ≤ C the fuel is returned directly to the fuel tank. If the returning fuel is ≥ C the fuel is returned via the fuel cooler. On cold start up the warm fuel is partial (75%) redirected to the secondary fuel pump which pumps the fuel back into the system to improve cold starting characteristics. If the bimetal valve allows the fuel to return to the tank, the fuel flows through a cooler. Cool external air enters the cooler through a ducted air guide and flows through the fuel cooler. In hotter climate markets there is an electric fan located in the ducting. The fan assists the fuel cooling by drawing extra air past the cooler thus improving the fuel cooling characteristics.
FUEL DELIVERY SYSTEM – TD6 DESCRIPTION AND OPERATION 19-1-15