Tough day out

My son invited some coworkers out for a ride with us. Awesome. Get to the boat start the engines port engine stalls and throws an IAC code. Restart every thing good. About 25 minutes out starboard engine overheats. Shut down immediately port into neutral. Port engine stalls, wont stay running , IAC code again. Open hatch, water all over starboard engine. Into spare parts box and had an old IAC that was working when I changed it. Swap it in, port engine running, limp home on one. Problem is when engine cooled and tried to restart to have power steering to dock, cranks fine but wont start. Any suggestions on where to start looking for problems with starting after an overheat episode? 2003 5.0MPI 

Comments

  • Pat310Pat310 ✭✭✭
    By the way leak in cooling causing overheat was rotted out plug in manifold that looks like someone replaced the brass one with a steel on. Uhggg
  • PickleRickPickleRick ✭✭✭✭✭
    Have you checked for spark?   I hope you were able to cut the engine before it got too hot. 
  • Pat310Pat310 ✭✭✭
    @PickleRick its Hard to say. Shutdown 5 seconds after buzzer sounded. Definitely not hydro locked so don’t think I warped head. Could fuel system vapor lock from heat?
  • PickleRickPickleRick ✭✭✭✭✭
    edited August 2023
    It can happen but it's rare on EFI high pressure systems.  

    I don't know if you're in salt or not but my thought is something electrical didn't like getting doused in water, causing a failure.   Loss of spark.   Hooking a timing light up to your motor and turning the key is probably the easiest diagnostic there is.  If it flashes you have spark, if it doesn't you don't.    Having two motors means you can start swapping parts to find the culprit. 
  • Pat310Pat310 ✭✭✭
    Thanks @PickleRick. Good advice (as always from you)  on a place to start 
  • PickleRickPickleRick ✭✭✭✭✭
    You're very welcome and good luck.  Hopefully it's something simple.  
  • Pat310Pat310 ✭✭✭
    edited August 2023
    More bad news. The salt water being pumped out like power washer hose was directly under the plastic flame arrestor cover and directly into the throttle body and the engine is now toast. For anyone with raw water cooled off this vintage engine GM sends engines to Merc with the steel automotive plug but list the replacement as brass. Very expensive find for me. Mechanic says not that uncommon. He’s seen it many times before
  • TonyG13TonyG13 ✭✭✭✭
    Ugh! Any chance insurance can/will cover the repair?
  • PickleRickPickleRick ✭✭✭✭✭
    That's crappy dude.   Sorry to hear. Not the simple fix anyone wants to see. 






  • Sorry to hear that.  All because someone couldn't put in the correct plug!

    Dream 'Inn III -- 2008 400 Express

  • sorry to hear
    2004 232
    2021 Yamaha Fx svho
  • PickleRickPickleRick ✭✭✭✭✭
    So since it's not our cash and we want to live vicariously through someone else's upgrades what's the game plan?  Replacement 5.0?  Perhaps a pair of 5.7 or 383....or even 6.2 upgrades?   

  • 8.1
    2004 232
    2021 Yamaha Fx svho
  • PickleRickPickleRick ✭✭✭✭✭
    Sometimes you need 1000 horse power 
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