2008 F15x Surging

[shwine617]

I finally got my F15x out for the first time.
It runs very smooth, but there is one issue.
when you hold it wide open for a stretch it surges.
the boost gauge bounces from 10psi to 8psi.

I can't figure out why it is doing this.
thanks

[jlfx car audio]

Heat soak. Theirs something keeping it from getting the cool water thru the ic good. Might ha e to pull screen out of pump and pull ic out and clean it out (probably got sand in it)

[Jake Speed]

I would check the wastegate arm on the turbo housing. Just oil it up and work it back and forth with a pair pliers.

[shwine617]

Thanks for the replies. I don't think it's heat soak because it will do it right away.
I will check the wastegate arm. The turbo looks brand new still. Only 30 hrs on ski.

Does the computer have fuel cut at a certain PSI of boost?

[JoeyDFZS]

Knock from bad fuel

[shwine617]

That's a good point Joey, Could be that. Would that cause the symptoms I explained? The gas is from last season, but I know the new gas doesn't last.

[JoeyDFZS]

It will retard the timing If knock sensor senses it, if it were me I'd do new plugs seafoam and fresh fuel

[abmobil]

The 12X skis are sensitive to the condition of the Spark plugs. I imagine the 15X are similar. Starting the skis, and not letting them get up to temp can foul them. Many people do this when launching their ski from the trailer. I would try new plugs, and see how it runs from there.

I had surge issues years ago. Plugs solved mine.

[shwine617]

Drained gas, put a blend of 100 and 93 octane in it, new plugs, and sea foam. Ski rips now. thanks guys!
also put a straight pipe on it from Ramon at H20 Extreme. Sounds nasty!

[JoeyDFZS]

Glad to help bro