1990 mercruiser 3.0 serial# 0D442882
I was running the boat the other day and all of a sudden felt a drop in power and rpm. I turned around and started heading for the dock and felt another sudden drop in power. Got back to the and started trying to figure out what happened. Now the boat will only start if the throttle is wide open and for approximately 20 seconds the engine struggles to keep running. Eventually the engine revs up and I can bring the throttle down to 1200-1500 rpm - any less and the engine dies and I have to repeat the same process again. I replaced the spark plugs, distributor cap, and rotor and saw no difference. While the engine is running, I can unplug number 3 & 4 wire from distributor and nothing happens. If I unplug either of the other two, it dies. Checked to see if plugs were firing and they're not. I then swapped with plugs and wire that were firing and plugs from number 3&4 cylinder still aren't firing. Any ideas on what is causing this?
I was running the boat the other day and all of a sudden felt a drop in power and rpm. I turned around and started heading for the dock and felt another sudden drop in power. Got back to the and started trying to figure out what happened. Now the boat will only start if the throttle is wide open and for approximately 20 seconds the engine struggles to keep running. Eventually the engine revs up and I can bring the throttle down to 1200-1500 rpm - any less and the engine dies and I have to repeat the same process again. I replaced the spark plugs, distributor cap, and rotor and saw no difference. While the engine is running, I can unplug number 3 & 4 wire from distributor and nothing happens. If I unplug either of the other two, it dies. Checked to see if plugs were firing and they're not. I then swapped with plugs and wire that were firing and plugs from number 3&4 cylinder still aren't firing. Any ideas on what is causing this?
Last edited: