Volvo Penta Fuel Pressure Drop

[Fireman431]

Trying to sort out a problem with a 2007 Rinker with a VP (I believe) 502. Only 80 hours on the boat. The fuel pressure slowly drops from 34 to 0 and the engine begins to make a whistling sound. The engine whistles loudly, coughs, and pressure comes back up, then runs fine. Then it does this cycle over again, taking a few minutes between rounds. The warranty mechanic has tried 2 seperate new fuel pumps without change. It is a MPI with throttle body. Any ideas?

 

[Gene70]

Re: Volvo Penta Fuel Pressure Drop

Get a automotive stethoscope. Remove the diaphram off the hose leaving just the tubing. Put the listening pieces in your ears with nothing on it but the vinyl hose. With the engine running go around the intake manifold gasket area and listen for compression leaking. Also check around the carburetor base gasket. If you have any blowing of air around the intake manifold then the intake is leaking. Bad gasket. This would be the most logical problem. If any of the above seems to be wrong then you will need to replace intake gasket and carb base gasket. This is not even in a service manual. I would be happy to discuss this with you.
Good luck.

 

[Don S]

Re: Volvo Penta Fuel Pressure Drop

If you post the SN or full model number of your engine, There are a number of things that can be checked once we determine exactly what model engine you have.