air at injection pump fuel inlet M-25XP

[chrisyse]

What are the steps/tricks to locate the source of air leak? After sitting for one week, I must bleed the vent at the injector pump on my 1989 M-25XP or engine shuts down after about 5 minutes. No air visible at Racor
Catalina 34 system: tank - racor - electric pump - seconary filter - injection pump - engine; connections seem tight. What is fuel pressue at the injection pump inlet? I am considering adding a gauge. Thanks

[bmm32005]

Start from the tank and work to the engine. I had a issue wit the pick up tube in the tank that had a soldered elbow that had a pin hole. No issues when the tank was full. As soon as I got to around 3/4 it would suck air. You also have the round valve that you can crack open and it will bleed itself when you turn the pump on. You can also just leave it open and it will continue to bleed the system.