Fuel pressure drop, engine looses power. 2007 nautique 206 limited 330 Excalibur

[Hintzy]

I just purchased a 2007 nautique 206 limited with 330 Excalibur from a friend of family. Boat has 58 hours. Original owner ever pulled a skier behind this boat. Garage queen boat in pristine condition. it does have performance problem, after 15 min cruise on the water at 2500-3000 rpm fuel pressure drops to 20 psi engine almost dies, let off throttle fuel pressure recovers to 50 psi runs perfect until it happens again several min later. all gauges and voltage good, no check engine litght has new battery too. Had local marina attempt to fix, they did high pressure pump and filter in fcc. Didn’t fix problem. Then did Carter low pressure pump same didn’t fix. Then did new fuel pressure regulator. Same. Then went to fuel tank pic up fitting, replaced with open barb fittings no anti siphon check same didn’t fix. Fuel vent tank vent is clean and clear. At a loss on what to check next…. Any one have ideas/ suggestions on what to look for. Thanks

[Rednucleus]

Nothing sadder than an almost 20 year old boat (or car) that has had no use (3.5 hr per year). Maybe time for all new fuel lines. Bet they are rotting and restricting fuel flow.

[Tom_H]

I don't recall if this applies to the excalibur, but there's a short section of hose off the high pressure fuel pump in the fcc that can cause some issues if it cracks or gets a pinhole, but yours sounds more like an eventual starvation of the fuel supply. I agree with Red, that I'd be starting with new fuel lines to/from the tank and any filters that are present (including the one in the FCC). If you haven't already, I'd also be pulling the pick-up tube out of the tank and inspect. I chased a similar issue that turned out to be a random plastic wrapper in the tank that lodged itself in the pick-up tube. Some pick-up tubes also have screens that can collect junk.

[Rednucleus]

Hope this works here - this is over on Ball of Spray
https://www.ballofspray.com/forums/t...=getNewComment

[Hintzy]

Definitely will be checking fuel hoses and pick up in tank. Thanks!

[SilentSeven]

Hmm. Boat that's sat that long could have some interesting 'old fuel' and rotted line issues. I'm with Rednucleus and Tom_H on this - a / replace the fuel lines b/ check the FCC and c/ consider if you need to flush the fuel tank for old fuel.

Oh - and you have to post a few pictures of the garage queen. 58 hours makes her a unicorn!

[Hintzy]

Boat fixed, After doing more investigation at the fuel tank pick up location and inspecting hoses and pick up tube, I see an aftermarket fuel filter has been installed right at the tank. See pic attached. With the filter added the hose also has a small loop and rise in the hose. I suspect this was causing the filter to hold air in the filter body and starve the fuel feed to the low pressure pump. The filter was very clean zero restriction in the filter. I removed the filter ran hoses level and back into original position and the fuel pressure problem disappeared and boat ran great all weekend. Doesn’t need 3 filters the fuel system boat has 1 in FCC and 1 at the Low pressure pump inlet. I suspect the low pressure pump doesn’t has a strong suction it is designed to push fuel. see a few pics of the boat.

[SilentSeven]

Nice. Posting a follow-up always gets you a board high-five!

Boat's clean. More pictures are required!