Fuel Temp Sensor

[Joel451]

Does it matter if the fuel temp sensor is on the supply side of tandem pump or return side ? Factory position is return side but I'm not sure if that is because of performance or just because it fits better there on a stock engine. Any one have some insight on this ?

 

[Vince Waldon]

Here's how I understand it:

Fuel temperature affects flame propagation time, and thus the ignition advance needed to compensate for fuel temp.

The ECU controls ignition advance, so it wants to know the temperature of the fuel as close as possible what it is as it gets injected to burn.

Since things get hotter when they are compressed/pumped the exit side of the tandem pump is a more accurate view of fuel temperature pre-combustion than the inlet side.