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No Start Without Throttle When Cold

picturethispicturethis Member Posts: 103 ✭✭
edited July 2014 in Engine Discussions

On my 2000 7.4 MPI when I turn the key when the boat is cold the boat will start then die,   but when I turn the key while giving it gas it will stay running.    After the boat is hot , the boat will fire up each time with no throttle.

not sure if these are related but

I recently replaced the starter solenoid and before I replaced it ...the solenoid clicked when I turned the key to the right (before it cranks).  Now after I replaced the solenoid, it does not click when turning the key. 

 Maybe I got a bad unit? 

I am a new boater with my first boat,  thats why some of my questions seem dumb

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    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭

    #1 sounds like an IAC issue.  

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
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    picturethispicturethis Member Posts: 103 ✭✭
    edited July 2014
    Can the IAC be cleaned or does it need to be replaced?

    will an automotive one be the same as a marine in this case?

    I am a new boater with my first boat,  thats why some of my questions seem dumb
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    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭

    It is off the back of your throttle body, it is what lets air in at idle for a fuel injected motor. Google it, there is a filter too. They are common to go bad. 

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
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    aero3113aero3113 Member Posts: 8,810 ✭✭✭✭✭

    You can replace the foam filter in it,some people remove the foam all together (not sure of this is recommended)

    2008 330EC
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    picturethispicturethis Member Posts: 103 ✭✭
    edited July 2014

    Where is this filter are you guys talking about?   I searched with no luck


    I know this isnt an marine IAC but I didnt see filter on it


    http://www.youtube.com/watch?v=VwO3k0Up_bw



    Post edited by picturethis on
    I am a new boater with my first boat,  thats why some of my questions seem dumb
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    Dream_InnDream_Inn Member, Moderator Posts: 7,559 mod

    To see the foam filter, you need to remove the flame arrestor.  Without it, you will get an annoying whistle sound at idle. & yes, the first part definitely sounds like an IAC valve.

    Dream 'Inn III -- 2008 400 Express

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    picturethispicturethis Member Posts: 103 ✭✭
    edited July 2014

    found the foam when I took the TB off.    I sprayed the IAC and throttle body down with gumout, put it back together and it fired up.  Im not sure if what I did was a short or total fix.  

    The iac from the boat store is going to take a week to get here .  But Advance Auto has it now.  (I cross referenced the part numbers .  it looks like the exact same part.   

    Any reason I shouldnt put the auto part in my boat if the gumout trick doesnt work?

    I am a new boater with my first boat,  thats why some of my questions seem dumb
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    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭

    personally, I am partial to OEM parts for electrical/fuel parts on mine.  I'm not sure if there is anything different about the auto IAC or not, hard to say sometimes.  Once they start to mess up you are better off to replace then try to clean IMO.  You are better off to replace that IAC filter too, help keep from sucking in dust and stuff into the valve..let alone the afore mentioned whistle.

    Someone must have that IAC in stock in the Detroit area, I'd call around. 

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
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    rinker312rinker312 Member Posts: 255 ✭✭

    if it were me and you did your research and it seems like the same part, I would just use the automotive part.  I don't think this is an electrical component that you need to be concerned about getting a proper marine part.  But that is just me.  I have had these go bad in the past also.  Often when they get bad they can also trigger an alarm.  I have had issues where placing an automotive part in triggers the alarm all the time, but that was not with the IAC, I have never tried an automotive IAC.  Good Luck

    2004 Rinker 312, 5.0 Merc's, Bravo III, Lake Wheeler, AL

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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭

    IAC's gotta jive with the merc tuning on the merc pcm... Chances are an automotive IAC works fine, but there is still a chance an automotive IAC sends a different signal value to the system, which merc will translate as "open more" or, conversely "close more" based off of stored parameters and other things going on with the engine, which is obviously idle rpm... 

    Since merc that year doesn't monitor a:f with an o2, it leaves the signals from temp, throttle position, and ambient air temperature as the triangulation to set idle, and of course reconciles it against actual rpm... Point being: ya better make sure the IAC is sending the proper signal, or it could upset the balance of an otherwise healthy engine... 

    I'd be willing to bet an automotive IAC is fine, and if it were my engine I'd chance it without hesitation, but just so you know........ 

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    picturethispicturethis Member Posts: 103 ✭✭
    thanks for the responses guys

    I am a new boater with my first boat,  thats why some of my questions seem dumb
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