Engine Stalls after 30 seconds

[Habber]

Hello Everyone- I have a 1997 Sea Ray 190 Signature with a 4.3 Lt engine. The engine is brand new last year, and I mean brand new. the only thing that is used is the card, everything else is new. The last 2 weeks when I start the boat at the Marina it will run for 30 seconds and shut off. It will start rite up again and do the same thing. I can do this all day long. I changed out the old gas - thinking I had water in the tank. I cleaned the tank completely. Put new High Octane fuel back in. Changed out the water fuel separator filter. Changed out the small inline filter just where it goes into the carb. Still does the same thing. Runs for 30 to 40 seconds and shuts off. I have also checked the fuel fill lines for obstructions and there is none. I'm at a total loss. Could it be the fuel pump? any advise or suggestions would be great. The fuel pump in not in the tank.

 

[gm280]

Have you checked the fuel pump output? Take the fuel line off the carb and crank it over to see if fuel flows out properly. If not, there is your problem. Also can you squirt some 50:1 fuel mixture in the carb and keep it running? If so then you certainly have a fuel delivery issue. And that can be the fuel pump, fuel lines, filters, carb float not working correctly, or anything in the tank that could be blocking the pick up. Time to make certain everything is clear and cleared... JMHO!

 

[Yachtsman1304]

I would also look at the "oil pressure switch". This post covers it well: http://forums.iboats.com/forum/engi...es/9962446-4-3-engine-stops-running-fuel-pump

 

[GA_Boater]

Try opening the fuel filler cap. May be a blocked tank vent.

 

[NYBo]

Definitely check the fuel tank vent line for kinks or obstructions.

Also can you squirt some 50:1 fuel mixture in the carb and keep it running?

Why 50:1 mix? This isn't a 2-stroke.

 

[bruceb58]

As a test, jumper past the oil pressure switch and make sure the fuel pump turns on. If it does turn on, then run the engine and see how long it runs for.

If it was a blocked vent, I would think it would run longer then 30 seconds. 30 seconds sounds like the amount of fuel in the float bowl. When the engine is cranked, the fuel pump is energized by the start circuit which fills the bowl.

 

[NYBo]

Would it really run for 30 seconds with no oil pressure??

 

[bruceb58]

Would it really run for 30 seconds with no oil pressure??

Bad oil pressure switch. The oil pressure switch is separate from the gauge sender.

Of course we are all assuming he is watching his oil pressure gauge. Maybe we shouldn't!

 

[UncleWillie]

Would it really run for 30 seconds with no oil pressure??

If the engine has an Electric Fuel pump, there are 3 Oil pressure Sensors.
One is the Sender to the Oil Pressure Gauge.
Another is the Oil Alarm pressure switch that Closes for Low Oil Pressure.
The third is the Fuel Pump Disable switch that Opens for low Oil pressure. <---<<<

If the engine were to stall, the Oil pressure drops, and the fuel pump stops, preventing the possibility of overflowing the carb.
This duplicates the action of a mechanical fuel pump that naturally stops when the engine stops.

While the Starter is engaged, a secondary circuit enables the fuel pump to fill the carb.
Once the engine starts, the oil pressure switch closes to keep the fuel pump running.
If the wire is Off the Oil pressure switch, the fuel pump will stop when the Start Key is released.
and the Carb will run out of fuel in less than a minute.
An engine restart will be slightly delayed, as the carb bowl will take a few seconds to refill.

After it stalls, if you look down the carb throat and Pump the Throttle ...
The accelerator pump should squirt fuel if there is still any fuel in the carb bowl. No Squirt = Dry Carb.
Start it up again and shut it down immediately. Accelerator pump working now? Fuel in Bowl!

 

[Habber]

Been a while guys, Thanks for all the reply's. Turns out it was a faulty oil pressure sensor