engine shutting down issue 1995 350

[johcap]

I have a 1995 Malibu Response with a direct drive Mercruiser 350HO engine that has a throttle body fuel injection system. When I start my engine when it's cold it runs like a champ for as long as I would like. But when I shut if off and it sits for between 15 minutes and even 4 or 5 hours, I then begin to have problems. It starts up fine and even runs for a few minutes, but after 3 to 5 minutes it sometimes shuts down. (more often than not at this point) It then stalls out and acts as though it's not getting fuel. I can try and start it again but it has to sit for a while before it will start back up. When this first started happening, it would start up within a few minutes. As this problem has progressed, it takes longer and longer before the engine will start back up. Sometimes it could be up to an hour and I have actually run the battery down once trying and then had to get towed in. If it starts back up it runs fine the rest of the time it's running. I have not checked the fuel pressure but I have checked to see if fuel is spraying in to the carburetor and it is. Once I tried spraying starter fluid in after this happened and it acted as though it would continue to run as long as I kept spraying but I wasn't sure if it would cause any damage so I left it alone at that point. I'm not sure if it's the fuel pump, the fuel system in general or even a sensor that's not allowing proper fuel flow. Somehow this problem occurs only after the engine has sat hot for a while. What could the heat build up being doing to cause the engine to do this? Does anyone have any ideas or suggestions on how to locate this problem? I don't want to just start replacing parts as a guess. Any suggestions would be greatly appreciated.

 

[skray]

Re: engine shutting down issue

Could be dirty fuel injectors/old/bad fuel, I have twin 5.0l EFI and had similar problems when the boat was new ran great until it got warm then would not restart without completely cooling down (it was vapor locking) In the end I had to instal in Electric fuel boost pump inline between the fuel tank and the fuel filter (pumps from mercruiser) Nerver had the problem since, still i'd start with cheap fix IE. clean the fuel injecters. Good luck