MIboatfreak
Recruit
- Joined
- Jul 17, 2019
- Messages
- 4
Hi everyone,
thanks in advance for any insight you might help me with here. I have a 1995 4.3 mercruiser I/O that I bought with a fuel issue. The engine only ran on a starting fluid charge.First I replaced the anti siphon valve. No help but cheap peace of mind. Then I traced and replaced the oil pressure cutoff switch and primed the system by disconnecting the fuel line from the carb and putting suction on it until fuel flowed. I replaced the line, primed and cranked. The engine started right up and idled fine. I thought the problem was solved but 2 problems are still here. After a week of sitting, the engine started after 1 priming pump of the throttle but only ran until the bowl emptied. I did my suction trick at the carb and it ran fine all day and the day after. My 2 problems: 1) When checking for an air leak, do I use a suction gauge or pressurize it with 4 or 5 psi? I assume that’s the only thing left after installing a new anti siphon valve? And 2) I notice that the electric pump runs when I first turn the ignition switch on, then stops after about 5 seconds unless I crank the engine. It does run as I crank and also when the engine is running. Other threads say that the pump should only run while cranking and while there is oil pressure. (Unless you have fuel injection which I sadly don’t.) I also read that it is normal for the electric pump to not prime. I’m here to report it does not. It Is vertically mounted on the engine just above the fuel/water separator and appears to be mounted as manufactured. Why is it losing prime? Should it suction feed itself back? Is it ok to run for a few seconds before cranking?(I love that it does that but if it ain’t right...) Thanks again
thanks in advance for any insight you might help me with here. I have a 1995 4.3 mercruiser I/O that I bought with a fuel issue. The engine only ran on a starting fluid charge.First I replaced the anti siphon valve. No help but cheap peace of mind. Then I traced and replaced the oil pressure cutoff switch and primed the system by disconnecting the fuel line from the carb and putting suction on it until fuel flowed. I replaced the line, primed and cranked. The engine started right up and idled fine. I thought the problem was solved but 2 problems are still here. After a week of sitting, the engine started after 1 priming pump of the throttle but only ran until the bowl emptied. I did my suction trick at the carb and it ran fine all day and the day after. My 2 problems: 1) When checking for an air leak, do I use a suction gauge or pressurize it with 4 or 5 psi? I assume that’s the only thing left after installing a new anti siphon valve? And 2) I notice that the electric pump runs when I first turn the ignition switch on, then stops after about 5 seconds unless I crank the engine. It does run as I crank and also when the engine is running. Other threads say that the pump should only run while cranking and while there is oil pressure. (Unless you have fuel injection which I sadly don’t.) I also read that it is normal for the electric pump to not prime. I’m here to report it does not. It Is vertically mounted on the engine just above the fuel/water separator and appears to be mounted as manufactured. Why is it losing prime? Should it suction feed itself back? Is it ok to run for a few seconds before cranking?(I love that it does that but if it ain’t right...) Thanks again