Results 1 to 6 of 6
  1. #1
    Roy W. Howard's Avatar
    Roy W. Howard Guest

    Default " Yesterday my 7.4L starting m

    " Yesterday my 7.4L starting making a metal on metal racket that seemed to eminate from the fuel pump area. Unfortunately, I was in a narrow channel with no place to pull off so I was forced to run the engine that way for some distance. The engine seemed to hold RPM, boat speed was unaffected, the coolant temperature and the oil pressure were all normal. But once I was able to pull out of the channel and brought the boat to idle, the engine ran rough and died. Would restart, but still had the noise and very rough idle. Is this typical of impending fuel pump failure or is it something else? Thanks in advance for the help. "

  2. #2
    croozertoo's Avatar
    croozertoo Guest

    Default "Not likely to be the fuel pum

    "Not likely to be the fuel pump unless it has worked loose from the block or the pushrod has shattered (I'm assuming a mechanical pump here). If the pivot or arm of the pump broke, you would likely have no fuel pressure at all.

    Inspect the engine closely, especially accessory driven items, check the plugs. If all looks good, given the good vital signs, I'd restart the engine and closely investigate the source of the noise. More info would help, like is it a grinding or hammering noise, and what part of engine it's coming from exactly.


  3. #3
    Join Date
    Jan 2004

    Default " If your having trouble ident

    " If your having trouble identifying exactly where the noise is coming from an old tool idea that can be used is a mechanics stethascope. They are available at parts stores and such, but you can also fashion one out of a short piece of garden hose and a small funnel. Slip the funnel into one end of the hose and hold that end near your ear. Using the other end of the hose probe the different areas of the motor, and the accessories until you have identified the source of the noise. Once you know where it is coming from it will no doubt be easier to diagnose the problem and this may be something that will work for you.

    Do be careful where you place the end of that hose to avoid getting it caught in moving parts on a running motor though. "

  4. #4
    Join Date
    Nov 2005
    Oregon coast, Oregon, USA

    Default " Does the ignition system use

    " Does the ignition system use a distributor with cap and rotor? If so lift the cap and check for a wobbly distributor shaft. I agree with the others that the symtoms don't point to the fuel pump and if it is, it is not typical of a fuel pump. "

  5. #5
    cer merc tech's Avatar
    cer merc tech Guest

    Default " You need to add the type,yea

    " You need to add the type,year of 7.4/454 engine you are running. I.E. carburated,multi-port with the large plenum or the l-29 series. is there a computer on this engine. either way the ignition system should be EST. Carbureted will have fuel pump off the seawater pump, MEFI 1 may have same fuel pump feeding into the older VST tank. MEFI 2 & 3 Will have cool fuel systems. I would perform a compression test and check spark plugs for rust. these motors are know for water ingestion on long idle times. what you are looking for is a seized or sticking exhaust valve "

  6. #6
    poker casino772's Avatar
    poker casino772 Guest

    Default "***** ****** [url=""]***** 71

    "***** ****** ***** 713"

Similar Threads

  1. Bravo I crunching noise
    By jcoyrochesterrrcom in forum Mercruiser Sterndrive Archive
    Replies: 1
    Last Post: 08-25-2009, 10:06 PM
  2. Need helploud noise coming from hipressure fuel pumpbad pump
    By jballow in forum Volvo Penta Gas Archive
    Replies: 7
    Last Post: 08-20-2008, 08:19 AM
  3. 97 Bravo 3 outdrive noise
    By JIM FAL in forum Mercruiser Sterndrive Archive
    Replies: 1
    Last Post: 08-19-2008, 04:32 PM
  4. Bravo III grinding noise when engaged
    By illgetu in forum Mercruiser Sterndrive Archive
    Replies: 2
    Last Post: 07-30-2008, 01:09 PM
  5. VP fuel pump noise
    By rodger in forum Volvo Penta Gas Archive
    Replies: 2
    Last Post: 08-28-2007, 08:18 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts