High Pressure Fuel Pump PSI

[ckrieg]

I have a Volvo Penta 7.4GI PNCACE

My high pressure fuel pump is whining and I'm trying to figure out why. I have a fuel pressure gauge hooked up, and it's reading around 40 psi, and dropping to 35-38psi when I rev to 2000 or 3000 rpm in neutral. Is that typical? Or is that reading low? I have not yet tested it under load.

I searched but wasn't able to find the answer to my question. The low pressure pump was replaced at the end of last year. The engine is not hestitating, but under WOT, it typically would reach 55ish mph, and is currently only capable of about 40mph.

Any thoughts would be tremendous!

 

[ckrieg]

While we're at it, ​as soon as they key is turned off, the pressure drops, should this not hold pressure for 5 or 10 seconds?

The low pressure pump is also making noise too now, almost like it's sputtering. What pressure should it be running?

 

[gbeltran]

No Title

Here you go.

 

[gbeltran]

Sorry but I can't seem to upload a full size image. PM me your email address and I'll send it if you cant expand the pic.