mercruiser 3.0 issues

duffyreef

Recruit
Joined
May 31, 2009
Messages
2
i have a 2000 sea ray 180 with a 3.0 mercruiser i/o this is my 2nd season with this boat. on first trip out this season engine would start and idle fine ...but upon trying to increase throttle motor stalls ...unless i can increase speed to over 2500 rpms quickly then again it runs fine. as soon as i throttle back to 2000 rpms the motor quickly stalls. engine restarts fine and idles fine in gear. had no problems last seaon beside a few dieseling events which going to middle grade fuel seemed to cure. i put in gas store at last seasons end .after talking to several mechanics the cures seem to be all over the place. iv'e owned boats all my life and i know to not just start replacing items without having a reasonable plan i think it seems to be fuel or fuel system related any help would be greatly appreciated Tim
 

danond

Lieutenant Junior Grade
Joined
Jun 11, 2007
Messages
1,118
Re: mercruiser 3.0 issues

Can you rev the engine? i.e. at idle, not in gear, can you pump the throttle, rev the motor and not have the engine stall? If so, it points to something other than a fuel issue.

There's an ignition interrupt switch on your engine that cuts the engine for just a split second when going into and coming out of gear. If that switch is sticking or your shift linkage is out of adjustment, it could kill the engine.

If you are dieseling you need something other than a fuel grade change.
 
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