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?

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.

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.

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.

Oh the joys of EFI.........All those little sensors and parts. Alphabet soup.

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.

yes...and wait till you get the price on that liitle jewel !!!

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!!!!!!!!!!!

Or maybe I should stay away from the Captain Morgan and go to bed!!!!!!

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!:D.BTW now I see both water pumps leaking, The list never ends. So much for my wallet.