Go Back  Offshoreonly.com > Owners Forum > Formula
PLEASE help 502 mag mpi efi dying out after run >

PLEASE help 502 mag mpi efi dying out after run

Notices
Formula

PLEASE help 502 mag mpi efi dying out after run

Old 07-30-2011, 04:48 PM
  #1  
Registered
Thread Starter
 
Join Date: Jul 2011
Location: Sorrycuse .N.y.
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Default PLEASE help 502 mag mpi efi dying out after run

New to forums.. Please some info. I on boat now and getting annoyed!
1996 SR1 271 502 mag efi/mpi. New boat for me
I pretty good On cars and most motors and issues but.... Here my prob
Bought boat used know nothing about history.
Starts right up runs great at all rpm's run all day fine... After sitting no matter if twenty mm or two hours fires right back up revs fine take off 25 yards starves out and quits????????
Will refire instantly but can't throttle up. After 8-10 restarts it will
Be fine?????? Changed all filters fluids and cleaned the VST filter?
Seems like a mechanical pump feeds VST mid back of engine? Seems to be fuel related but cannot be 100% sure till
More test... It's just really annoying and making me mad. After it
Re starts it's totally fine runs like new.... And this repeats all
Day long WTF UGHHHHHHHH
IamEdZ is offline  
Old 07-30-2011, 06:17 PM
  #2  
Registered User
 
Boat Doctor's Avatar
 
Join Date: Dec 2007
Location: Lexington S.C.
Posts: 53
Likes: 0
Received 0 Likes on 0 Posts
Default

try opening the engine hatch when you stop and run the blower it sounds like its vapor locking.
Boat Doctor is offline  
Old 07-30-2011, 06:27 PM
  #3  
Registered
 
Join Date: Jun 2009
Location: League City, Tx
Posts: 339
Received 0 Likes on 0 Posts
Default

Check the vent for the fuel tank

Almost sounds like a loose ground wire or a battery cable that's loose
TooTall is offline  
Old 07-30-2011, 08:32 PM
  #4  
Registered
Thread Starter
 
Join Date: Jul 2011
Location: Sorrycuse .N.y.
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Default

i cleaned every ground and battery terminal when i first got it..i am not ruling anything out but hate the guessing game.
thanks so much for fast replies guys..... i tried open enginge hatch everytime... no help..its so so weird ran so good all day i can go full speed or idle around for hours..once i shut off for either 20 min or 2 hr same thing fires right up then can idle or take off fast go about 20yrds and starves out..then back to the 10-12 key starts till it back........ gut feeling with my car knowledge is saying fuel issue.. i dont fully understand the system can someone break it down to me

line goes in by sea pump but its not a mechanical pump like my 454 just looks like round diaphram,,,,then up to vst tank with a float and chamber leacing to pump chamber with filter on bottom...... so the part by the sea pump feeds the vst.... so is that pressure regulated or no? ..

far as the fuel lock i tried taking gas cap off when it was happening and it made no difference..also no problems when filling the tank but not sure if fill vent is related to tank vent when under load?? man i am boggled.. just want to find exactly what it is and fix so i not guessing and doing this when i go out..

gonna try homeade code reader monday afternoon.. also anyone know if codes are stored even when batt switch is off or do i need to reproduce the problem again before pulling codes??? THANKS FOR ANY IMPUT IN ADVANCE!!!
IamEdZ is offline  
Old 07-30-2011, 08:40 PM
  #5  
Registered
Thread Starter
 
Join Date: Jul 2011
Location: Sorrycuse .N.y.
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Default

why two fuel pumps...... seems foolish design read about alot of guys getting rid of this set up?

http://www.boats.net/parts/search/Me...LOW/parts.html

http://www.boats.net/parts/search/Me...ANK/parts.html
IamEdZ is offline  
Old 07-30-2011, 08:46 PM
  #6  
Registered
iTrader: (2)
 
Join Date: Aug 2005
Location: Between A Womans Leggs in IL
Posts: 6,306
Likes: 0
Received 1 Like on 1 Post
Default Fixx

Originally Posted by IamEdZ
i cleaned every ground and battery terminal when i first got it..i am not ruling anything out but hate the guessing game.
thanks so much for fast replies guys..... i tried open enginge hatch everytime... no help..its so so weird ran so good all day i can go full speed or idle around for hours..once i shut off for either 20 min or 2 hr same thing fires right up then can idle or take off fast go about 20yrds and starves out..then back to the 10-12 key starts till it back........ gut feeling with my car knowledge is saying fuel issue.. i dont fully understand the system can someone break it down to me

line goes in by sea pump but its not a mechanical pump like my 454 just looks like round diaphram,,,,then up to vst tank with a float and chamber leacing to pump chamber with filter on bottom...... so the part by the sea pump feeds the vst.... so is that pressure regulated or no? ..

far as the fuel lock i tried taking gas cap off when it was happening and it made no difference..also no problems when filling the tank but not sure if fill vent is related to tank vent when under load?? man i am boggled.. just want to find exactly what it is and fix so i not guessing and doing this when i go out..

gonna try homeade code reader monday afternoon.. also anyone know if codes are stored even when batt switch is off or do i need to reproduce the problem again before pulling codes??? THANKS FOR ANY IMPUT IN ADVANCE!!!
My insurance mans boat,,had a similar problem..he would start out with a full tank of fuel,,run out 5 miles and go fishing,came back into the harbour and his boat would die out..(fuel issue) So i removed the the fuel pick up in the tank and inspected it, it was a aluminum pick up tube,so when i tryed to check and see if the tube was threaded into the *90 fitting the pipe broke off in my hand where the threads are..called a tank mfr and they sent me a updated nylon fuel pick up..he said that the aluminum ones always seem to crack at the joint..

boat ran fine on a full tank of fuel and once the fuel went down to 3/4 and you were on plane it was ok cuz the fuel in the tank covered the crack in the pipe..
FIXX is offline  
Old 07-30-2011, 08:58 PM
  #7  
Registered
Thread Starter
 
Join Date: Jul 2011
Location: Sorrycuse .N.y.
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Default

interesting...but i cannot make this happen its only after driving wether i run up and down lake full bore for hour or little while.... what i dont understand is it runs totally fine wot or idling...its just a resart issue? also not sure how choke works on efi... hoping something stupid like intake air sensor or coolant sensor or something... motor was supposedly redone 90 hrs ago so who knows and i know nothing about guy or shop who did it..have some recipts but they dont tell much...got to love a new boat..my last 252br was totally fine....now new headacke...lol seems like a cycle i buy boat fix everything i can for two years or 3 then sell get new pain in the butt.. lol soon as i get them perfect i sell ans start over..someone tell me why? lol
IamEdZ is offline  
Old 07-30-2011, 09:01 PM
  #8  
Registered
Thread Starter
 
Join Date: Jul 2011
Location: Sorrycuse .N.y.
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Default

i will be cheking all suggestions btw thanks again
IamEdZ is offline  
Old 07-30-2011, 09:19 PM
  #9  
Registered
Thread Starter
 
Join Date: Jul 2011
Location: Sorrycuse .N.y.
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Default

kinda wonderin if float inside vst is messing up...seems on restart i get as far as that amount of fuel would go then dies..maybe its sticking and not filling vst so when vst empty it quits??? not sure but every cold start 1st start of day never have issue
IamEdZ is offline  
Old 07-30-2011, 09:33 PM
  #10  
Registered
 
Join Date: Jun 2009
Location: League City, Tx
Posts: 339
Received 0 Likes on 0 Posts
Default

When you try to restart the boat, do you hear the fuel pump "prime itself" for 2-3the seconds before starting?

If you have an electrical meter, sitting the battery should read 12, running, it should be 14v. . . M m
TooTall is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.