Idle Issue
 

I am having an idle problem in a buddies 2001 Sea Ray 34. It has 2000 Merc Horizon 454's MPI if I am ot mistaken. The starboard motor will not start with the throttle at idle. It must be elevated slightly and the allowed to warm to operating temperature. Once at operating temp the throttle can be returned to idle and will idle until shifted. Upon shifting the motor will die. The rpm gauge is showing 750-800 in neutral and 650 ish in forward tied to the dock (when it will run). Vacuum is around 12" at idle. The boat runs great over 1000 rpm....
Thanks,
Ken

It is probably your idle air control or throttle position sensor, try pulling the idle air control out and cleaning it up, could be gunked up.