No fuel pressure

jmoen438jmoen438 Posts: 95Member ✭✭✭
So, had a great start the holiday weekend then Friday I texted Tikihut saying all is well, not an hour later the boat died. Luckily I was still in sight of the marina and got towed back by a dock neighbor on a jet ski, much to the delight of everyone on our dock, so many cameras were out I thought the paparazzi had landed. Thought it might be the fuel pump, replaced it, then figured out it was the oil pressure sensor, replaced it, ran great all day on Saturday. Went to fire it up this morning, wouldn't start. Fuel pump wouldn't cycle when you turned the ignition on, no fuel pressure at the Schrader valve. Ran a hot wire to the fuel pump and it ran fine. Sooooo, long story short, fuel pump isn't getting juice. Any thoughts? Yes, first thing I checked was the kill switch.


  • mvnmvn Uxbridge, OntarioPosts: 617Member, Moderator mod
    Just guessing here..... Is there a fuel pump relay? If so, has it gone south? Check all your connectors?

    Good,  fast,  cheap.... pick two. 
  • 212rowboat212rowboat Posts: 2,285Member ✭✭✭✭✭
    +1 on the relay.... but...

    is your rig totally PCM controlled?  It could be you need to take the harness off and clean it good- and pop it back on in hopes that it's a bad connection..

    just an ominous FYI- when PCM's start to release the ghost, electrical systems start to go wonky...
  • TikiHut2TikiHut2 Sarasota, FlPosts: 1,431Member ✭✭✭✭✭
    edited July 2013
    Jetskis....who would've figured they'd be handy for something ;) Glad you weren't far from home.

    Did you test the oil sender and old fuel pump to see if it was actually bad? If the starter engages and the engine turns over it may not be the harness connector but I'd have to say I'd start at the harness connector too. One of the 1st things I did after buying our 270 was pull the connector, even though there wasn't a problem, cleaned it, added some connector goo and put all back up. It's the usual culprit of electrical weirdness and an easy place to start.

    Marks input is certainly on target with the fuel pump relay and other connectors too.

    You said you checked the kill switch but does that mean you actually pulled it apart and jumped it? There was an old post where someone mentioned a cracked sw/rotten connection that intermittently failed causing a huge amount of hair loss and was eventually solved with a $10 part.

    Maybe all this is related to your 3-foot-itis altouth your 270 is a great boat ;)  Hope it's an easy fix. I hate quirky gremlins. Al may have some insight too. Good luck. Mike
    2004 FV270, 300hp 5.7 350mag MPI Merc 305hrs, 2:20 Bravo3 OD w.22p props, 12v Lenco tabs, Kohler 5kw genset, A/C, etc.etc...
    Regular weekender, Trailer stored indoors, M/V TikiHut, Sarasota, Fl
  • 212rowboat212rowboat Posts: 2,285Member ✭✭✭✭✭
    edited July 2013
    there are a ton of pins on the PCM, and it may be a dancing short between some of them due to exposure or corrosion- which may not effect them all, all the time... which makes diagnosing them a royal PITA..

    check your grounds, jmoen, especially the PCM's ground..

    check for continuity between harness connector terminal 86 and ECM/PCM harness connector A-19, if the relay isn't found to be an issue...

    here is a schematic and reference

    edited to add: if the relay does turn out to be the problem, your job still isn't finished.. you'll be needing to figure out what happened to it and why, or you'll likely be in the same place 'fore too long..
  • jmoen438jmoen438 Posts: 95Member ✭✭✭
    Great tips, thanks!
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