Power loss VP 5.7 Gi-D (with Video)

[dacarter]

I noticed some sputtering last time I had the boat out a month or so ago, but it seemed to have full power. Yesterday I had it out again and it didn't have enough power to plane out. Also had some of the sputtering, but it idles fine, and seems normal at low speed.

It's a 2003 Larson Cabrio 270 with 700+ hours. I remember reading all the black paint issues here, so decided to pull the fuel pump assembly and took it apart. There is some corrosion and flaking paint where the filter seal meets the housing, and a few small spots in other places, but doesn't look as bad as some of the pics posted here. Bench testing the pumps, they both spin. Haven't checked the pressure regulator screen yet. There's no whining sound that I've noticed.

I'm not finding lots of posts on how to clean the flaking paint, and since it's 10 years old, I might just spring for a new assembly, but would like to verify it's a fuel problem. Any other suggestions?

Here's a video of the engine while trying to plane the boat. I assume the ticking noise is pinging because it's running lean? I didn't try planing it out again, but did drive it around for several hours fishing at low speed and it did fine.

https://onedrive.live.com/redir?resid=A72756E8EED6FAC1!2407&authkey=!AOKZCWzC7l4RprU&ithint=video%2c.mp4

 

[MikDee]

Re: Power loss VP 5.7 Gi-D (with Video)

Hows the anti-siphon valve? Is it clean, can you blow thru it one way, but not the other?

 

[raven1978]

Re: Power loss VP 5.7 Gi-D (with Video)

Just out of curiousity, when was the last time you pulled the distributor cap off. I worked on a few boats that displayed those exact symptoms and the contacts were corroded all the hell, and the pinging/snapping noise was the spark finding the closest path to ground.

 

[gbeltran]

Re: Power loss VP 5.7 Gi-D (with Video)

You should really test the pump with a pressure gauge. My 5.0Gi pump didn't whine either when it was going out.

 

[dacarter]

Re: Power loss VP 5.7 Gi-D (with Video)

The anti-siphon valve is between the pump assembly and the tank right? Haven't checked it yet.

There no obvious blockage of either pump inlet screen or the pressure regulator. I'm starting to think that I don't have the black paint problem.

I have never had the distributor off (I've owned the boat for 1 year), but I think I have a receipt where the distributor was replaced in the last few years. I'll take a look. Related to that, I had a leak in my transom shower that may have dripped some fresh water on the top of the engine a month or so ago. The leak is fixed, but maybe related if ignition is the cause.

I don't have a pressure gauge that will fit the VP fittings, but may have to buy one.

 

[dacarter]

Re: Power loss VP 5.7 Gi-D (with Video)

Ok, I just pulled the anti-siphon from the top of the tank. If I blow really hard, I can get some air though in the direction of fuel flow, but but it takes a lot of effort. How free flowing should it be?

 

[MikDee]

Re: Power loss VP 5.7 Gi-D (with Video)

It should be firm in the direction of flow, and a no go opposite the flow. It should almost sound like a whistle as your blowing against the ball, & spring.

 

[dacarter]

Re: Power loss VP 5.7 Gi-D (with Video)

Ok, so maybe the anti-siphon is ok, but I'm going to get a non-anti-siphon fitting at Lowe's tomorrow in case I need it for further testing. I'm also going to take a look at the distributor and cap tomorrow. I found a receipt that they were replaced in 2012, but still could be an issue. The receipt says the distributor screws were corroded and stripped out and had to be drilled, so that should be interesting.

Thanks for all the replies. Hopefully I'll get it figured out soon.

 

[dacarter]

Re: Power loss VP 5.7 Gi-D (with Video) - SOLVED!

Re: Power loss VP 5.7 Gi-D (with Video) - SOLVED!

Raven1978 would win the prize if there was one. The contacts on the distributor are badly corroded. I have a receipt showing it's only 2 years old, but I guess these parts have a really tough environment, and I do use the boat in the salt water. I see that NAPA has the parts, so will give that a shot.

I hope my fuel pump assembly goes back together without issue...

 

[dacarter]

Re: Power loss VP 5.7 Gi-D (with Video)

Anti-siphon valve now deleted, new distributor and cap in place, fuel pump assembly all back together and she's running sweet. Won't know for sure till it's in the water, but I think it was definitely the distributor. Thanks for everyone's input.

 

[raven1978]

Re: Power loss VP 5.7 Gi-D (with Video)

Fwiw, i would re-install the anti siphon valve after you are done your testing for saftey sake, as for the cap, yeah they are in harsh enviroments and dont last too long. Glad to help out

 

[dacarter]

Re: Power loss VP 5.7 Gi-D (with Video)

I did some reading on the anti-siphon and have decided I don't need it's safety or want the future failure point. I take the boat offshore occasionally and really need good reliability. My gas tank sits well below the level of the engine and all fuel components, so I don't see how it could ever provide any safety in my situation. The way my heat exchanger sits, it would be nearly impossible for the fuel line to become severed and fall below the level of the fuel in the tank. I also learned that they are not required by law if the tank is below the level of the fuel components.

 

[jimmbo]

Re: Power loss VP 5.7 Gi-D (with Video)

I also learned that they are not required by law if the tank is below the level of the fuel components.

Is that as per USCG?

 

[MikDee]

Re: Power loss VP 5.7 Gi-D (with Video) - SOLVED!

Re: Power loss VP 5.7 Gi-D (with Video) - SOLVED!

Raven1978 would win the prize if there was one. The contacts on the distributor are badly corroded. I have a receipt showing it's only 2 years old, but I guess these parts have a really tough environment, and I do use the boat in the salt water. I see that NAPA has the parts, so will give that a shot.

I hope my fuel pump assembly goes back together without issue...

That's a cheap automotive cap! A marine Dist. cap has a different (better) plastic, and brass, or copper terminals to prevent corrosion
not cheap aluminum like this one!

 

[jimmbo]

Re: Power loss VP 5.7 Gi-D (with Video)

The old "marine parts are way over priced, the same part can be bought at Pep Boys for 75 % less" story. Never ends

 

[MikDee]

Re: Power loss VP 5.7 Gi-D (with Video)

The old "marine parts are way over priced, the same part can be bought at Pep Boys for 75 % less" story. Never ends

Pep Boys have Bosch premium spark plug wires, and probably a premium Bosch Dist. cap, or an equivalent that is great, & reasonable

 

[jimmbo]

Re: Power loss VP 5.7 Gi-D (with Video)

Pep Boys have Bosch premium spark plug wires, and probably a premium Bosch Dist. cap, or an equivalent that is great, & reasonable

Is the Dist. Cap USCG approved?

 

[MikDee]

Re: Power loss VP 5.7 Gi-D (with Video)

Maybe, maybe not? don't know if they have marine parts :embarassed: But, marine dist. caps are made better, like a marine version of Accel, Mallory, & Blue Streak. That's why they're more expensive, but worth it!

 

[dacarter]

Re: Power loss VP 5.7 Gi-D (with Video)

Thanks for the info on the dist cap. I didnt realize there was a difference. It wasnt all that cheap at $57. I put a $76 new GM oil pan on my engine last year that is exactly like the $400 VP pan, so I am skeptical about high priced marine parts.

 

[jimmbo]

Re: Power loss VP 5.7 Gi-D (with Video)

The oil pan for my 5.7 VP is different from a stock GM pan as it has the dipstick tube attached to the bottom of the pan. That said. You can probably get away with using the NonVP part there. However, Do Not substitute items in the fuel system, Ignition, Starting system, and charging system with Automotive versions. Marine parts have to meets certain USCG requirements that reduce the chance of your boat exploding. The cost will be higher because the lower production volumes but the parts are not the same.