Go Back  Offshoreonly.com > Technical > General Q & A
502 mag dies at idle >

502 mag dies at idle

Notices

502 mag dies at idle

Thread Tools
 
Old 05-04-2008 | 10:28 AM
  #1  
Thread Starter
Registered
 
Joined: Aug 2007
Posts: 276
Likes: 0
From: San Bernardino, Ca.
Default 502 mag dies at idle

2000 mpi mag. Ran out to catalina island yesterday. When I left the marina all was fine. After crossing the channel I dropped the throttles back and the starboard engine died.will not run with the stick at idle position. If I move the stick forward a bit it will run and idle fine. Almost like there is slack in the cable. I can idle both motors fine with starboard a little bit ahead of port, as I throttle up onto plan I have to even up the sticks to maintain even RPM on both motors. so anything past 1/4 throttle is even. This motor should idle when the throttle hits the stop but it does not. Any thoughts?

Last edited by zx14; 05-04-2008 at 10:37 AM.
zx14 is offline  
Reply
Old 05-04-2008 | 11:23 AM
  #2  
Dave_N's Avatar
Registered
 
Joined: Jan 2005
Posts: 573
Likes: 1
From: Newport Beach,CA
Default

It sounds like a Idle Air Control valve failure. You can just change it out and hope that's what it is, or connect up a scan tool and verify the problem, either way, it may be an easy fix.
Dave_N is offline  
Reply
Old 05-04-2008 | 12:09 PM
  #3  
Thread Starter
Registered
 
Joined: Aug 2007
Posts: 276
Likes: 0
From: San Bernardino, Ca.
Default

ok, swapped throttle bodies with the port motor. and all works ok, so I would say its the IAC. Any way to test these? ok just buy a new one.
zx14 is offline  
Reply
Old 05-04-2008 | 12:22 PM
  #4  
Dave_N's Avatar
Registered
 
Joined: Jan 2005
Posts: 573
Likes: 1
From: Newport Beach,CA
Default

Your IAC is a stepper motor type and you would need a IAC tester to properly test it. You can do a test of sorts by listening to it while turning the key on and then off. When the key is turned off the IAC resets and you should be able to hear it. If you don't hear anything, it probably isn't working.
Dave_N is offline  
Reply
Old 05-04-2008 | 02:06 PM
  #5  
Registered
20 Year Member
 
Joined: Jan 2002
Posts: 2,053
Likes: 39
From: Further South East of Dome Island
Default

Oh the joys of EFI.........All those little sensors and parts. Alphabet soup.
Pismo10 is offline  
Reply
Old 05-04-2008 | 07:08 PM
  #6  
Registered
 
Joined: Aug 2005
Posts: 1,491
Likes: 0
From: sint maarten
Default

sometimes you can save them w/ lubrication and 'exercising" them by taking them off and pushing them back and forth... its as if some kind of contamination jams them occassionally.
stevesxm is offline  
Reply
Old 05-04-2008 | 07:26 PM
  #7  
Registered
 
Joined: Nov 2005
Posts: 4,554
Likes: 3
From: Fredericksburg, Va
Default

yes...and wait till you get the price on that liitle jewel !!!
ezstriper is offline  
Reply
Old 05-04-2008 | 09:50 PM
  #8  
spazboz's Avatar
Gold Member
 
Joined: Dec 2006
Posts: 1,150
Likes: 5
From: Zeeland, Michigan
Default

Sometimes they just plain aren't happy. Maybe, you havn't talked them in a while, or you aren't in touch with they're needs. Maybe one motor feels like you like the other one is better than the other one. Who knows. Maybe the port motor set-up the stbd motor b-cause it was jealous of the power-steering pump! Who knows? Twins engine boats are like having two girlfriends, its a trecharous game to play!
My 2 cents, Nick!!!!!!!!!!!
spazboz is offline  
Reply
Old 05-04-2008 | 09:52 PM
  #9  
spazboz's Avatar
Gold Member
 
Joined: Dec 2006
Posts: 1,150
Likes: 5
From: Zeeland, Michigan
Default

Or maybe I should stay away from the Captain Morgan and go to bed!!!!!!
spazboz is offline  
Reply
Old 05-05-2008 | 06:50 AM
  #10  
Thread Starter
Registered
 
Joined: Aug 2007
Posts: 276
Likes: 0
From: San Bernardino, Ca.
Default

Well I am going to get back at that SB motor. I am leaving ports TB on it and when the new IAC shows up, port gets it, and it gets SB TB. I'll show that SB motor whos boss!.BTW now I see both water pumps leaking, The list never ends. So much for my wallet.
zx14 is offline  
Reply


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

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.