My original installer recommended against an on-board fuel water separator saying that it just increased resistance in the supply line and that the on-motor separator was all that was required. I have tried to go with his advice but I just can't stop worrying about this issue.
Finally, caving to my paranoia, I decided to install the on-board separator on my own and did so last week with a Racor 3214 clear bowl and Racor Vacuum gauge setup. I have read the service manual and the pre-delivery guide but I still have questions about priming the fuel system of an AF model G2. From my read of the service manual it appears that the system self-primes on turning the ignition key. What happens to the air in the fuel line? Does it pass thru the lift pump and eventually clear via the vapor separator vent solenoid and then on to the plenum? I ask because I am installing a fuel water separator and while I am sure that there are no air leaks in the system, a small amount of air/vapor collects in the fuel line after the engine is turned off. This air sits in the supply hose until throttle up and then is sucked into the the motor - I assume that's where it goes. Is this normal or is it a threat the the health of the motor.
I am also wondering if you normally prime the system after changing out the fuel water separator simply by turning the key and letting the lift pump pull fuel through the fuel lines until all of the air in the new filter is displaced by fuel. Or do you purge the system by using a squeeze bulb temporarily placed at the end of the fuel line before it connects to the fuel lift pump inlet hose under the front cover. The manual does not mention purging the air in this manner. I assume it is not necessary.