stillcantfly
Seaman Apprentice
- Joined
- Sep 13, 2019
- Messages
- 37
hey guys I have been combing through form after form and spent a lot of money still can't fix the issue. I have a 350 mag MPI tournament ski serial number 0L671154 has 239 hours on it. I can't get this stupid thing to stop the suction noise coming from inside the throttle, before you tell me I need a IAC or the IAC muffler mine doesn't have the muffler.I have replaced the IAC with a new Mercruiser one. still making the suction or hissing noise and she won't go below 1000 RPM. and boggs down when trying to pin it from idle. if I go slow till about 1800 RPM I can pin it and she's perfect no hesitation. I have replaced fuel injectors, fuel filter, fuel pump (ouch) IAC, throttle body, coolant temp sensor, air temp sensor, pvc valve, TPS, MAP sensor, I AM SO FRUSTRATED, BUSTING OUT ANOTHER THOUSAND. been on the phone with merc they said do a leak down test? compression is perfect. it only has 239 hours on it. can yall please help. I can't find a vacuum leak any where. I've sprayed WD40 around throttle body nothing, around PVC valve and hose to the throttle body still nothing. around valve covers nothing. when I pull the vacuum line off on the other side going to the fuel pressure regulator nothing changes nor are there any leaks I can feel a little suction but that's it. that all the vacuum system right?. and no fuel coming out of the fuel regulator either from the line between it and the throttle body? line is dry I think that good....exhaust I can't see being the problem she has a lot more then normal coming out the back... white too not black but does leave black soot on the boat when in the water. please help! I'm stumped.
Last edited by a moderator: