5.0 gxi-d backfiring and power loss .

[kccoe]

I took boat out after lower unit repair and overheat due to seal left out on pickup tube and other issues. After repairs the boat ran fine 5 miles up lake and back . Then after sitting for about 30 minutes to let kids swim I started boat back up andwent to wot and boat sputter , backfire and pop and pump whine. Never got back on plane. Stop waiting 15 minutes then boat ran fine , but got afraid of being stranded went on in to dock. Temps seem ok unless sensor is bad. This has happen twice. I have check fuel lines and the fuel pressure regulator screen and all is good. The Volvo mechanic is a month behind so is there any suggestions or any thing else I could check. It has a new fuel pump.

 

[Thalasso]

Have you tried checking the fuel pressure on the low side pump.

 

[kccoe]

Have you tried checking the fuel pressure on the low side pump.

Yes and guess what I found today. A loose Schrader valve on low pressure pump side . It was spraying a very fine mist for a second when my wife turn key switch to on position to activate fuel cell. When I was pressure testing. I removed valve by hand from pump housing. The high pressure pump was likely sucking some air . I also found a loose connection on the wiring harness at the low pressure pump by accident . I bump the connection by hand when pressure testing and the plug came loose. The wire clamp was only half in at a odd angle. Ran the boat for two hours no problems with no power loss and no backfiring. The bad news is I checked my out drive oil and I got milk color lube . WATER in outdrive lube after I purchased a rebuilt lower unit and had a Volvo dealer installed and pressure check . . I am just about ready to give it up.