I have a 2006 Mercury 115ELPT4S that will not start after stoppping and sometimes will stop while running and not restart. It has been on diagnostic computer a bunch with no codes except a voltage code fault at 302 and 808 hours and rectifer was replaced each time. ISC valve failed test and it was just replaced also. Fuel lines,pickup, and all filters replaced. Low pressure fuel pump and high pressure fuel pump and filter also replaced. Fuel rail pressure is 41 pounds even when it will not start. Engine sometimes will not start for ten to thirty minutes. Motor currently has 1108 hours and is run almost daily in my business and always run ethanol free gas. The problem has gotten worse and stops now everytime we have the boat out. When we get the boat back to the shop and hook it up to the computer it always starts. My tech says that the only thing let is to replace the ECU for the motor. I still have ignition concerns but tech says it should start in limp mode. It never occurs during a cold start only after motor has reached operating temp. It was doing once or twice a month now it is almost every time the boat is out so I know it is getting worse. I purchased this motor new in 2008 and it has been on the same work boat since then and nothing has changed. I spoke with another Merc mechanic and he suggested changing out the motor controls to eliminate that possibility of problems with coil knock off for shifting. Just curious if anyone has experienced ECU problems with these symptons before I pull the trigger on a new ECU.
