Having an issue with my 2002 Mercury 115 EFI 4 stroke going into limp/guardian mode. It has been doing this for about a year now and it might have started after I replaced the water pump impeller. Can't remember exactly. I have replaced the water temp sensor, oil pressure sensor, thermostat, tach, and battery cables. Sometimes it will go for a couple weeks and never act up, and sometimes 4-5 times a day. Yesterday, I started it and backed out of the slip and it started. Been running about 45 seconds. Sometimes I can run it for 1/2 hour before it acts up. I will pull it back into neutral and sometimes that will reset it and other times I have to turn the key off to reset. Water seems to be very strong coming out the piss hole. I took the thermostat out, put the housing back on, pulled the hose off and started the motor and the water came out like a fire hose when I rev'ed it up some. Put in a new thermostat anyhow. Checked all the grounds I could find and put new battery cables on. I replaced the tach because the needle was jumping all over the place. There is no beep, beep, beep, just a steady long beeeeeeep until I restart the motor.
Any ideas are very much welcome.
Thanks
John