fuel pumps

[spotpatch]

I have a 7.4 fuel inj. Volvo 1999. when I turn key on, pump clicks to prime, I start engine and then I get a loud whine from the high (rear) fuel pump. Engine is running. But before that, I started it last week and ran full throttle for about 15 to 20 minutes then all of a sudden it went to half throttle and I couldn't get any more out of it. I got back to dock, shut it off , restarted it , no whine. ran around for 5 minutes then shut it off. restarted it ande now it whines again. and each time I start it , it whines from what seems to be the back pump. Is the high pressure pump going bad or is the low pressure pump bad by not giving the high one enough fuel??

 

[sandkicker]

" ran at full throttle for 15 to 20 mins"..... i.e., the fast track to the repair shop.

 

[Bluecollerboater]

The wine is because the screens on the fuel pump are clogged up. Take the pump out and clean the inlet screen and the wine will go away.