Hi, I have a 1997 Merc 350 MPI EFI with 125 hrs on it and it was running fine until a few days ago. It starts up fine then the rpms drop to 400 from 600 and almost stalls before it increases in idle speed up to about 1000 rpm an the engine seems to be making a sucking more air sound. Once I give it some throttle in neutral it seems to go back down to 600 rpms and stays there. Out on plane it will rev to 5000 rpm and runs perfect for as long as I hold the speed I am at but if I slow down and then accelerate quickley, it will bog down and I have to pull back the throttle a bit before I advance the throttle slowly to get it up to full rpms. If I am at idle speed in gear and gun the throttle a bit it did stall and then the engine would turn over for a while before it would start which is not normal for an EFI engine which always starts on the first shot. I changed the fuel/water filter and put in injector cleaner but no change occured. The filter did have some crude in it though. I always hear the fuel pump making 2 sounds when I turn the key to on. Any opinions.
Thanks
Thanks