Fuel delivery issues

[bluestreak3599]

I have a '02 caravelle interceptor with a volvo penta 5.0 gxi-c engine. My problem is the high fuel pump is making that whining noise that i have read about on here. the boat acted like it was starving for fuel the last time i took it out and would bog down on acceleration. I took the whole fuel cell off and cleaned it the best i could, but no way to clean the pumps real good. installed it back on and chkd the pressure on the high pressure side. it seemed high, but not sure. it pegged out at 100psi or more. couldnt chk the low pressure right now cause the valve was smaller. now, when i tapped on the fuel pressure monitor cylinder, the whine cut in and out and stopped. and, all of these tests are out of the water, and not under full load and the whine would normally start rising when it was revved up and brought bk to an idle. but, all i would do was tap on that cylinder and the whine would stop.. any ideas on what it could be.. and i also have changed the anti-syphon valve coming from the fuel tank

 

[WSUDERMAN]

Re: Fuel delivery issues

100 psi is really high. Whats your confidence level in the gauge accuracy?
I don't know that motor but I belive that should be closer to 60 psi. The Fuel Regulator controls the pressure so if yours is stuck closed it would drive the pressure up and make the pump strugle to maintain it, could be why it's whining.
This would also cause your motor to run very rich - The injector timing is based on 60 psi, @ 100 psi they are going to be putting out alot more fuel. You should see some black residue from this on your exhaust and be able to smell the excess fuel.

 

[bluestreak3599]

Re: Fuel delivery issues

thanks for the info WSUDERMAN.. the guage i used was sort of questionable seeing the condition it was in, but it did relieve the pressure bk to 0psi, so i'm not sure.. there is some residue from the exhaust, but i didnt think it was anymore than usual..as far as the fuel regulator goes, is there any special way to change that out or at least chk it. if i pull it out, would it throw anything off or is it just pretty simple. it dont look to be that hard to take out. i would like to chk it out, at least, and rechk the pressure..anymore info would be greatly appreciated

 

[WSUDERMAN]

Re: Fuel delivery issues

As far as i know the only way to test it is with a pressure gauge. I really don't know your motor so you are going to need a manual to get the specifics the correct pressure and on pulling the regulator.
Also, you should Check the low pressure side as well. a bad low pressure pump can starve the system as well. This might help validate your gauge since the low side should be no more ~8 psi.
I would try to validate the gauge accuracy either with another gauge or a fixed pressure source like an air compressor.
On my 7.4 the regulator was not to bad to remove and it had a screen on the inlet side that was rather pluged from bad fuel.

Wes

 

[bluestreak3599]

Re: Fuel delivery issues

yeah, i was gonna chk the low pressure side too, but the valve was smaller and i didnt have a different connection size for it. i'll do some more chking and researching to find out on the fuel regulator, but it looks to be simple, thnx for all the info. i'll post afer chking