View Full Version : Stalling

05-07-2006, 11:30 AM
My 2003 5.0L MPI 260 HP Mercruiser Gen 2 alpha is starting fine when cold. Once the engine is warmed up it has a hard time starting and stalls at idle. If you get it started you have to then gun the gas to get it going and once up it runs great.

05-07-2006, 11:36 AM
"Try opening the throttle a little and see if it's easier to start. How clean is your flame arrestor? If it's dirty, clean it. If cracking the throttle makes it easier to start, you may have a sensor issue or the IAC may not be re-parking in the right place. Have you checked the fuel pressure?"

05-07-2006, 03:11 PM
"flame arrestor cleaned and not helping, how do I check to see if I am loosing fuel pressure? THe engin will only start if the primer starts first!"

05-07-2006, 03:42 PM
"I assume the MPI stands for Multi Port Injection, right? There should be a Shrader valve on the fuel rail so a fuel pressure gauge can be attached. If the pressure is low, it could be bad gas (water or debris in the tank), bad impeller from running the tank dry, clogged fuel pickup tube, clogged fuel tank vent, etc. Without knowing anything about how the boat and motor have been maintained, it's just about impossible to tell what the problem is, from here."

05-07-2006, 06:21 PM
"Thanks alot, it looks like it was just a matter of cleaning the flame arestor, there was a small vacumn filter below it that I also cleaned, it was just kind of stuffed into one of the vacumm areas