Quote:
Originally Posted by AKOne
Question: Is the OEM fuel filter upstream of the lift pump or downstream?
|
If you consider the “stream” as fuel flowing from the tank to the engine, then the fuel passes through the water separator/filter
before it reaches the lift pump, therefore that filter is
upstream of the lift pump. Common rail engines often have a second filter between the lift pump and injector pump, and that filter would be downstream of the lift pump.