Vacuum Leak Hissing Noise 2002 VLX

[Bosstic]

Whatsup Guys! Hope your all having a great week! First off, thanks for everything you do in helping people in our community. Its truly the best.

Did my spring tune up last weekend in Parker AZ. Did a water test after I was complete , fired up the boat and the idle was very rough and I heard a distinct HISSING noise. Continued to reverse off the trailer and when I put the boat in gear to go forward, it died. Did this a couple of times and once the engine is warm after about ten mins and pressure has been accumulated the idle goes back to a normal state and the boat goes in/out of gear without dying. I read a few posts on vacuum hose leaks and it sounds like my issue. Where should I begin looking for leaks, and should I be using a stethoscope? How many vacuum lines are on a 5.7 Indmar Monsoon? I've used the garden hose and screwdriver trick in the past lol. Does this sound like a vacuum leak, TPS issue, or AIC valve issue to you guys? Thanks for all your help, once again this community is the best!

Also have a non working fuel gauge, which I had bakes test! Gauge is good, cannot find problem from tank to gauge. I've checked most grounds and ground buss. Any info helps! Thanks guys!

[tvano]

i can't remember stuff.  

consider, if the engine is cold the throttle plate will be closed when it starts.

that causes lots of air "hissing" noise.

once warmed up that throttle plate opens and the air flow noise is much reduced.

could this be the cause of your concern?

lumpy rpm and stalling is common on a cold carbureted engine.  is yours carb or fuel injected? 

[Bosstic]

Fuel Injected. I don't believe its throttle plate.

[justgary]

Get the throttle body clean before you continue to troubleshoot.  A can of spray carb cleaner is your friend.  Be sure to get the side passages clean as well, since this could be nothing more than a gummy IAC pintle.