Lost of Pressure in Vapor Seperator

[Burstie]

Losing pressure in vapor seperator. Electric pump will give me 38 PSI for the first 30 seconds, just like the Mercury Manual states, after the 30 seconds pressure is down to zero. Checked injectors and hoses no injectors are stuck open and no leakage at hoses, also checked pressure regulator it checks out. If you depress the bleed off stem when the pump is not running you have no pressure at all. I am also losing pressure when motor is running pressure drops to approx. 20 to 22 PSI. Friend has the same engine and his maintains pressure even after the 30 second cycle is complete. Engine is a 175 EFI Mercury.

 

[vinney]

Re: Lost of Pressure in Vapor Seperator

You need a fuel pressure guage hooked up to the engine. Next put a volt meter on the high pressure pump on the vapor seperator. The fuel problem is a supply problem or pump pressure problem. If this engine has sat for any length of time I have seen the pumps get hurt from the old fuel. If you have added a water fuel seperator inside the boat I seen that cause a high vacuum problem.