Mercruiser 5.0 stalls after about 1 minute

[hirschaj]

I tried searching for an answer to my problem but found nothing.<br /><br />My engine starts and runs just fine with no sputtering or anything. After about 1 minute it just stops. This happens every time I start it. It doesn't matter if I am idling or running higher RPM's. The voltage, oil pressure, and temps look just fine. The boat has been in storage all winter and was winterized before being put away. Does anyone know what would cause this?<br /><br />Thanks for any advice,<br />Jim

 

[Haut Medoc]

Re: Mercruiser 5.0 stalls after about 1 minute

What year? Carb or efi? Welcome to iboats ....JK

 

[Reel Poor]

Re: Mercruiser 5.0 stalls after about 1 minute

We'll need a little more info. What year. Can you post your engine serial number?<br /><br />Is it Carburated, TBI injection, or MPI?<br /><br />Does it restart after it dies? If so, do you have to wait for a while or will it immediately restart?<br /><br />Have you done a tune up or anything other maintinance to it?

 

[hirschaj]

Re: Mercruiser 5.0 stalls after about 1 minute

THanks for the quick replies.<br /><br />It is a year 2000, Carburated, I don't have the serial number at the moment (will post that a little later).<br /><br />Yep, it restarts right away....Crank a few times while giving some gas and starts right up.<br /><br />I had it tuned up at the beginning of the last boating season (last April timeframe). Also, the ignition control module was replaced with a new one in the middle of summer. Other than that there has been nothing done recently besides the impeller and oil changes.<br /><br />Thanks again for any advice you can give.<br />Jim

 

[Don S]

Re: Mercruiser 5.0 stalls after about 1 minute

Probably a defective oil pressure switch (NOT sender) or the wiring to the switch. Item 5 in the drawing below. Pull both wires off the switch and hook them together and start the engine. If it runs, you found your problem. The terminals tend to get rusty on them.<br /><br />

 

[Reel Poor]

Re: Mercruiser 5.0 stalls after about 1 minute

I would at least change the fuel filter. When you remove the old filter pour the contents of the old filter in a flat pan of some sort and see if there is trash or water contaminating the fuel.<br /><br />If the engine shuts down like someone turned the key off it's most likely going to be an electrical issue.

 

[hirschaj]

Re: Mercruiser 5.0 stalls after about 1 minute

Thanks for all the info. I am going to check the oil pressure switch in the morning. I do need to change the fuel filter as well. I will let you know what happens.

 

[marinemech1]

Re: Mercruiser 5.0 stalls after about 1 minute

don is probably right oil pressure switch wires may have got knocked off when it was winterized<br />the switch when closed provides power to run the electric fuel pump

 

[rodbolt]

Re: Mercruiser 5.0 stalls after about 1 minute

check what DonS is teling ya <br /> its baffeled many a tech.<br /> when ya hit the starter the pump runs from the solinoid while cranking and will fill the fuel bowl, at engine run the circuit is through the oil pressure switch,not sender, and if the connections corrode it wont run the pump and the carb goes dry only to refill the next time the starter solinoid is engaged.<br /> if the switch is hard to get to place a voltmeter on the purple yellow to ground at the choke, if the switch is bad or lost connection you lose voltage at the choke as well as the fuel pump.

 

[hirschaj]

Re: Mercruiser 5.0 stalls after about 1 minute

Don S you are a genius!!! I disconnected the 2 wires, scrubbed the terminals with a wire brush and reconnected the wires. The motor fired right up and stayed running until I shut her down. <br /><br />rodbolt, great tip on that purple yellow wire at the choke. I was able to easily get to the pressure switch but if I couldn't that wire is right on top and a piece of cake to get to.<br /><br />Many thanks to all who replied.

 

[Bayl305]

Re: Mercruiser 5.0 stalls after about 1 minute

Probably a defective oil pressure switch (NOT sender) or the wiring to the switch. Item 5 in the drawing below. Pull both wires off the switch and hook them together and start the engine. If it runs, you found your problem. The terminals tend to get rusty on them.<br /><br />

Hi Don

Can u please tell me where the oil pressure swich is located? NOTsender?
Regards from Norway

 

[Hanmar]

Re: Mercruiser 5.0 stalls after about 1 minute

Probably a defective oil pressure switch (NOT sender) or the wiring to the switch. Item 5 in the drawing below. Pull both wires off the switch and hook them together and start the engine. If it runs, you found your problem. The terminals tend to get rusty on them.<br /><br />

My oil pressure switch has only one wire coming from it