2005 Mastercraft X Star problem

[Mattymillz12]

So, I just recently bought a 2005 Mastercraft X star with the 6.0 Cadillac engine. The boat is gorgeous and runs great 90% of the time. On occasion the boat will decrease in speed and almost want to come to an idle. All gauges seem to be good with the exception of a ballast gauge not reading correctly, but I'm curious if anyone has had a similar issue with the engine? The boat starts and idles fine, but doesn't want to hold speed (large fluctuations) randomly when running. Any advice is awesome!


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[bet_on_black]

Has the fuel pump been replaced? The ballast gauges can be adjusted but are finicky.

[snork]

only time ballast gauge work is when your tanks are full
I'd look into a new fuel pump and filter and TPS

[Mattymillz12]

Has the fuel pump been replaced? The ballast gauges can be adjusted but are finicky.

The fuel pump hasn't been. Could it still be the fuel pump even if the boat starts and idles perfectly? It's only when accelerating that there is an issue. And it's random

[Mattymillz12]

only time ballast gauge work is when your tanks are full
I'd look into a new fuel pump and filter and TPS

What do you mean by TPS? And I have heard a lot about the fuel pump and filter. Where's the best place to get one online for the make/model.

My marine dealers/mechanics around here suck and take forever

[ttu]

The fuel pump hasn't been. Could it still be the fuel pump even if the boat starts and idles perfectly? It's only when accelerating that there is an issue. And it's random

do a research in the fuel pump thread. when mine started to go out it would run great and then do the same are you are stating.

pretty sure TPS throttle position sensor.

[Mattymillz12]

do a research in the fuel pump thread. when mine started to go out it would run great and then do the same are you are stating.



pretty sure TPS throttle position sensor.

That's super helpful! I definitely gonna try to find the right fuel pump. Do you suggest a new fuel filter as well?

[Chris_b]

Went through the same thing on my 05 Xstar. I had to replace the fuel sending unit and the throttle sensor.

[Mattymillz12]

Went through the same thing on my 05 Xstar. I had to replace the fuel sending unit and the throttle sensor.

Do you know where I could get those? Hoping that will solve it. Did you do anything with the fuel filter?

[snork]

Fuel filter is attached to the bottom of the fuel pump assembly

[Mattymillz12]

Fuel filter is attached to the bottom of the fuel pump assembly

Have any input about the throttle sensor?

[Gavin]

That's a great looking star! Sorry I don't have any experience with your issues but any marine mechanic worth a darn is going to be swamped right now.

[Mattymillz12]

That's a great looking star! Sorry I don't have any experience with your issues but any marine mechanic worth a darn is going to be swamped right now.

That's my problem sadly. But I appreciate that! Just bought it a little over a week ago

[Jerseydave]

Buy yourself a fuel pressure gauge and connect it to the test port (looks like a threaded tire valve on the fuel rail)
Key on, engine off.....reading should be 53-58 psi

If pressure checks out okay, try to check it again when the engine acts up.

Many times the fuel pump will get hot and not produce pressure until it cools back down again.

Have you or the previous owner ever run the boat out of gas? Or even low on gas?
You should never run below 1/4 tank, the pump relies on gas to keep it cool.

Fuel filter is on base of fuel pump module in tank.
Where in the northeast are you located?

[Laneberg1]

You can rent/borrow the fuel pressure gauge at AutoZone. I think it was actually free, they charge you for it then refund when you return.


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