Engine won't run after back flushing raw water system

[wingo812]

Help, Please!!

I have a 2004 24V with 6.0L PCM. Engine running hot (bought boat a year ago used) and wanted to change coolant and and thermostat just cuz anyway. New impeller, new thermostat and new coolant in and boat went smoothly right up to 250 degrees again. After shutting down and consulting here on tigeowners forums, I decided to back flush the raw water system in case there were impediments to water flow. After the flush, the engine will start, but won't stay running. I made sure there is fuel. I suppose it's possible that the fuel pump and or fuel relay failed coincidentally with the flush, but really??!!

Any help would be appreciated. Thanks

[Z1Fan]

So it starts and how long does it keep running ? That means the fuel pump is pressureizing the fuel rail , .....if it starts

[LKG PH Creek]

I had that problem once. 97 5.7L EFI Mercruiser. Boat would start, but would stall before I could get it in gear. Over and over, start/stall...start/stall....start/stall... Happened at the July 4th fireworks. Turns out it was out of gas (even though the fuel gauge read 1/4 full)

[wingo812]

Engine is now running after sitting for 48 hours...weird. However, temp gauge is slowly creeping up to full pegged hot. I'm stumped as it has a back flushed raw system with new impeller, new thermostat, and new coolant. Only think left is circ pump, or faulty gauge or temp sensor. Any suggestions?