fuel leak, can't locate source

[2ndwish]

Must be the summer of fuel leaks. We just had the fuel line from the engine filter to the bleed valve rupture (and yes it was gold painted). Finding the leak wasn't too hard, but one trick made it easier. The bleed valve had been left slightly cracked open and this reduces the pressure in the fuel line (dramatically). Closing the bleed valve all the way made the small drip turn into a fine spray which was easily visible when the top engine cover was removed, creating a bright scene to view from the side doors. One thing I can't explain- the pressure in that line also increased when the engine was started vs just running the pump on battery. My guess is the wiring harness voltage drop causes this but maybe someone here can explain why that would happen.

BTW, replacing that fuel line was a PITA as all hoses are with tight fittings in tight quarters. 

[Ron Hill]

2nd : I hope you also replaced the "Gold" painted return line from the aft injector to the bracket on the engine. 

Guess you just don't get that 50 year quality anymore!   

[captran]

over a month and still no leaking.  In talking to a mechanic he suspects it was the fuel return line at the back by the injector and that as I was tightening everything, maybe it took a few days for whatever was there to dribble down, hence the bad one day, and the next only a quarter of the prior day and then nothing since.  this year has been interesting.  I also think my rpm/speed issue was due to a bunch of sea grass I must have gone through when I went below to grab something, as it has been a non issue since as well, which is really embarrassing.  might have saved myself some stress had I tried reverse and maybe been able to dislodge what was there.

[captran]

No drips for the last 4 weeks of the August-September cruise.  Started up the boat this year and maybe noticed one or 2 drops after 8 hours.  going to keep an eye on things.  Have done all of the above except the advance auto parts UV kit.  going to see if one of those is near Anacortes.  have wiped all down, looked with mirror.  just a slight film of fuel residue where the picture I posted last year.  checked the bleed valve, connections, but have not replaced the hoses yet.  but the weather is great and except for that, boat is wonderful.

[captran]

ended the last 4 weeks with no drips.  this year, after 8 hours noticed maybe one or 2 drips.  as I did last year, carefully checked all fittings, injectors, lines,  bleed valve...anything connected to the fuel system.  nothing. no sign of any fuel except where the original picture I posted.  very perplexing indeed.  I almost wish it was leaking a drop a minute.  would be easier to locate that way guess the next step is to try to locate one of the UV  detector kits.