Mercruiser 5.0 MPI (s/n 0m340696) with an Alpha outdrive on a 2001 Sea Ray Sundeck 210.
Starts and idles fine. When I splashed it for the first time this year it would run at idle speed but as soon as I opened the taps past 1500 rpm or so it would just die — no sputter, no hesitation, just dead — and would restart with no trouble and continue idling. Backstory: Taking it out of storage I accidentally reversed the battery cables (I know...I’m in hell). Let the smoke out, fried the alternator and a couple cables. I replaced all that, plus new switch and charging relay. So I figured I must have fried something else. Took it to a Merc tech to have them run diagnostics. They replaced the IAC but could find no other sensors or parameters out of the ordinary. Got it back from them and it will now rev and plane, but still randomly dies — can be at any point above, say, 1800rpm. No real rhyme or reason. Starts right up again. I fueled it over the weekend and it died three times in quick succession after the fueling, then settled down and cruised for a half hour at 2200rpm with no trouble. Try to open it up, dies. Starts, makes another 20 min run at 3200 on plane with no issues.
So I’m thinking random fried wire somewhere that’ll take me forever to chase down, but given the behavior after fueling I decided to throw on a new fuel-water separator. But it won’t self prime. Cycled the key several times and it just wouldn’t fill the filter. I primed it with some gas and fired right up.
Did I find my problem? Bad fuel pump? Or do I keep looking for electrical gremlins?
Starts and idles fine. When I splashed it for the first time this year it would run at idle speed but as soon as I opened the taps past 1500 rpm or so it would just die — no sputter, no hesitation, just dead — and would restart with no trouble and continue idling. Backstory: Taking it out of storage I accidentally reversed the battery cables (I know...I’m in hell). Let the smoke out, fried the alternator and a couple cables. I replaced all that, plus new switch and charging relay. So I figured I must have fried something else. Took it to a Merc tech to have them run diagnostics. They replaced the IAC but could find no other sensors or parameters out of the ordinary. Got it back from them and it will now rev and plane, but still randomly dies — can be at any point above, say, 1800rpm. No real rhyme or reason. Starts right up again. I fueled it over the weekend and it died three times in quick succession after the fueling, then settled down and cruised for a half hour at 2200rpm with no trouble. Try to open it up, dies. Starts, makes another 20 min run at 3200 on plane with no issues.
So I’m thinking random fried wire somewhere that’ll take me forever to chase down, but given the behavior after fueling I decided to throw on a new fuel-water separator. But it won’t self prime. Cycled the key several times and it just wouldn’t fill the filter. I primed it with some gas and fired right up.
Did I find my problem? Bad fuel pump? Or do I keep looking for electrical gremlins?
