BIG 1996 Shamrock 220 WA Project

Discussion in 'General Conversation' started by boataddict, Aug 17, 2021.

  1. fisherlady2

    fisherlady2 Well-Known Member

    Messages:
    918
    Likes Received:
    150
    Joined:
    Oct 5, 2016
    Location:
    Punxsutawney Pennsylvania
    Most tanks have an anti siphon valve, after years of sitting it may be clogged. Other possibility is that the fuel lines themselves have degraded from sitting with ethanol fuel in them.. Try running the system on a portable tank to see if it draws fuel without problem. If it draws fuel we'll then the problem is in the tank end of the system, not your fuel pump end.
     
  2. boataddict

    boataddict Well-Known Member

    Messages:
    76
    Likes Received:
    15
    Joined:
    May 19, 2020
    Location:
    Point Pleasant, NJ
    I've already checked and I have no problem getting fuel from the tanks. I'm definitely dealing with an issue past the new fuel pump, which I'm certain is siphoning fuel.
     
  3. Jonnydime

    Jonnydime Active Member

    Messages:
    28
    Likes Received:
    0
    Joined:
    Sep 7, 2021
    Do you have a low oil pressure fuel switch. My 26’ has one that stuck off on me the other day. It shuts the fuel pump off if there is under 5psi of oil pressure.
     
  4. boataddict

    boataddict Well-Known Member

    Messages:
    76
    Likes Received:
    15
    Joined:
    May 19, 2020
    Location:
    Point Pleasant, NJ
    That's a good possibility. I'm not sure if I have one. Where did you find yours and how did you solve that issue?
     
  5. boataddict

    boataddict Well-Known Member

    Messages:
    76
    Likes Received:
    15
    Joined:
    May 19, 2020
    Location:
    Point Pleasant, NJ
    I have a suspicion that this part is the culprit. Seems like a second pump? PXL_20210912_122709842.jpg
     
  6. Jonnydime

    Jonnydime Active Member

    Messages:
    28
    Likes Received:
    0
    Joined:
    Sep 7, 2021
    I know mercruisers have two pumps. A low pressure supply pump and a high pressure pump for the fuel injection.
     
  7. boataddict

    boataddict Well-Known Member

    Messages:
    76
    Likes Received:
    15
    Joined:
    May 19, 2020
    Location:
    Point Pleasant, NJ
    My suspicions were correct. Found the culprit. Going to order a new one this week and hopefully I'll be one step closer to firing it up next week. PXL_20210912_135335401.jpg
     
  8. boataddict

    boataddict Well-Known Member

    Messages:
    76
    Likes Received:
    15
    Joined:
    May 19, 2020
    Location:
    Point Pleasant, NJ
    Well, I installed the new one and am getting good pressure to the TBI. Still no start though. Got a couple squirts from one of the injectors but overall still not really getting them to fire consistently. I'm thinking at this point I need to remove and rebuild the TBI, probably have a clog somewhere from sitting? What do you guys think? It's really the final thing I haven't replaced in the fuel system.
     
  9. Bach Wilson

    Bach Wilson Well-Known Member

    Messages:
    81
    Likes Received:
    13
    Joined:
    Sep 16, 2018
    Are you certain they are supposed to be firing?

    Do you have spark?

    Are the batteries turning it over fast enough for it the TBI to sense starting?
     
    boataddict likes this.
  10. deputyrpa

    deputyrpa Well-Known Member Supporting Captain

    Messages:
    1,177
    Likes Received:
    81
    Joined:
    Aug 28, 2010
    Location:
    Fort Ann, NY
    What is your voltage reading at the injector heads when cranking? It should be above 9 volts to spray.

    IIRC, there is a screen in the injector bodies which may be clogged from sitting.

    But first make sure you're getting adequate voltage from the ECM.
     
    Last edited: Sep 18, 2021
    boataddict likes this.

Share This Page