Results 1 to 8 of 8
  1. #1
    Join Date
    May 2009
    Location
    Bartlett, TN
    Boat
    SeaRay SunDancer 240 DA
    Details
    1999 SunDancer 240 DA.
    Engine(s)
    5.0 Mercruiser
    Posts
    9

    Help! Merc 5.0 - Is it Fuel Pump?

    We are new owners of a used Sundancer 240 DA. 5.0, fuel injected Mercruiser. We have had random issues with it not starting. At first, would run great till got hot, then not start for 20 - 30 minutes. Then start and run great again. We listened to great advice and tried all the remedies for vapor lock. Apparently that isn't it because now it will do the same thing sometimes after sitting in slip all night and try to cold start.

    It is random, but getting more often and taking longer to start. Have replaced fuel filter (water separator) put the additive in gas tank in case of water or ethanol issues. A mechanic (didnt look at it - wouldn't work on Mercruisers) said he thought it might be fuel pump getting weak. Could this be it? Any ideas to make that diagnosis? We can replace ourselves if we know this is it. Thanks All!!
    Sea Ray Newbies
    '99 Sundancer 240 DA
    Bartlett, TN (Pickwick Lake)

  2. #2
    Join Date
    Oct 2006
    Location
    Wisconsin - Winnebago Pool chain of lakes
    Boat
    Sea Ray
    Details
    280 Sundancer, Westerbeke MPV generator
    Engine(s)
    twin 5.0's w/BIII drives
    Posts
    4,504

    Re: Help! Merc 5.0 - Is it Fuel Pump?

    Try this IAC test.

    Take the boat out of gear. You do this at the throttle. Itís likely a black button you push.

    Now manually advance the throttle. Does the boat start as normal now with you manually controlling the throttle?

    If this works itís the IAC or idle air control valve, a part that costs about $100 and is about the simplest do it yourself engine repair you could imagine.

    If it still does not start then itís not the IAC.
    2003 280 Sundancer twin 5.0 BIII
    Westerbeke MPV Gen added Feb '08
    Presentation

    Where we're going we don't need roads-Emmit Brown a.k.a Doc

  3. #3
    Join Date
    Apr 2009
    Location
    PA
    Boat
    Sea Ray
    Details
    1999 260DA ShoreLand'r Galvanized
    Engine(s)
    5.7L EFI Bravo III
    Posts
    8,912

    Re: Help! Merc 5.0 - Is it Fuel Pump?

    Boy, that's weird - usually it's really easy to find a mechanic to work on Mercs.

    Another idea:

    I don't know the spec, but you can check fuel pressure to verify if pump is bad. There's been a number of posts about fuel pumps - you might be able to find the info with a search.
    Dennis
    1999 260DA 5.7L EFI B3
    2000 ShoreLand'r
    Past & Other Current Boats: Not enough room!
    "Exceeding your expectations since 1936"

  4. #4
    Join Date
    May 2009
    Location
    VA
    Boat
    Sea Ray
    Details
    300 Sundancer 2002
    Engine(s)
    5.0 Mercs w/Bravo III Drives
    Posts
    25

    Re: Help! Merc 5.0 - Is it Fuel Pump?

    I've had similar problems with the fuel filter and IAC. I would go ahead and replace the IAC. As previously stated, it's 100 bucks, but it will probably go out soon if it's not the current fix as they are a weak link. Good luck and please post the fix when you have it.
    Family Time
    2002 300 Sundancer
    5.0L BIII

  5. #5
    Join Date
    May 2009
    Location
    Bartlett, TN
    Boat
    SeaRay SunDancer 240 DA
    Details
    1999 SunDancer 240 DA.
    Engine(s)
    5.0 Mercruiser
    Posts
    9

    Re: Help! Merc 5.0 - Is it Fuel Pump?

    thanks for the adivice. We have tried to start it by manually advancing the throttle, but it still won't start. We will keep ruling things out till we figure it out. Thanks again.
    Sea Ray Newbies
    '99 Sundancer 240 DA
    Bartlett, TN (Pickwick Lake)

  6. #6
    Join Date
    Dec 2008
    Location
    tx
    Boat
    sea ray
    Details
    Too many to count!!!
    Engine(s)
    Too many to count!!!
    Posts
    130

    Re: Help! Merc 5.0 - Is it Fuel Pump?

    Need to have the boat hooked up to a c.d.s. to see what the real problem is. I'm dumb founded that the "tech" would not work on a merc..... There has got to be a certified merc tech in your area with access to a c.d.s. Got a marine max in you general area? If so give them a call... If i wasnt in tx i would give you a hand, but that a little to far for a lake call for me!!!

  7. #7
    Join Date
    Apr 2009
    Location
    PA
    Boat
    Sea Ray
    Details
    1999 260DA ShoreLand'r Galvanized
    Engine(s)
    5.7L EFI Bravo III
    Posts
    8,912

    Re: Help! Merc 5.0 - Is it Fuel Pump?

    Any mechanic - even automotive - can check fuel pressure.
    Dennis
    1999 260DA 5.7L EFI B3
    2000 ShoreLand'r
    Past & Other Current Boats: Not enough room!
    "Exceeding your expectations since 1936"

  8. #8
    Join Date
    Oct 2006
    Location
    Baltimore, Md.
    Boat
    Sea Ray
    Details
    370 Sundancer 1995
    Engine(s)
    8.1s (2013) w/ V drives
    Posts
    828

    Re: Help! Merc 5.0 - Is it Fuel Pump?

    I have the same engine in our '99 210 bowrider, it was doing the same thing you are describing. Over time it would take longer and longer to start. Turned out to be the slave starting solenoid, had it replaced three years ago and has been fine since. If I remember correctly the part was $25.

    John
    Last edited by xravenx; 07-13-2009 at 08:01 AM.
    '95 370 DA w/T8.1s (2013) - "Michele Ann"
    '99 210 BR w/5.0 & Alpha 1 - "XRAVENX"

    Past Sea Rays - '88 268DA, '89 280DA, '88 21' Laguna, '90 310/330DA

    http://clubsearay.com/signaturepics/sigpic473_1.gif

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