Need little help with a fuel problem

[fjm308]

I have a 99 VIP with a 5.0L Mercruiser my boat starts up fine but only runs for about 40 sec so i disconected the fuel pump and ran it straight to the battery and it stays running. check the plug and im not getting my 12v from where ever it is comming from. just need to know what feeds the electric fuel pump and where can i get the part number?

 

[HT32BSX115]

Re: Need little help with a fuel problem

Howdy,

5.0L Mercruiser

You'll probably need to reveal a little more info on what you have. Sounds maybe like an MPI engine?.....

Engine serial number helps a lot since Mercury lists parts and specifies manuals by serial number instead of actual year model. Your 99 model boat may have a 99, 98 or even a 97 model year engine installed.

The engine serial number is usually back by (above) the starter.

 

[Silvertip]

Re: Need little help with a fuel problem

Engine with electric fuel pumps have a protection feature that shuts off current to the pump if the engine dies. The oil pressure switch does that. But since the engine has no oil pressure until it starts, there is a bypass feature that allows the pump to run when the key is turned on. That allows the engine to engine start. When you let go of the key after starting, the pump now relies on the engine oil pressure to activate the main circuit to the pump. Apparently the oil pressure switch or the wiring between it and the pump has an issue.

 

[LAC_STS]

Re: Need little help with a fuel problem

That same thing happened to me on my 5.7. It was a wire I knocked loose on the oil pressure thing right above the oil filter.

Check the connections and see if one is loose or off.

 

[zbnutcase]

Re: Need little help with a fuel problem

And bumpin a wire off is real easy to do while changin the oil filter.

 

[fjm308]

Re: Need little help with a fuel problem

the engine serial number is OL376047

 

[dubs283]

Re: Need little help with a fuel problem

yes, check the wiring for the oil sender/switch

i think there may even be a sticky about it in DIY'r section at the top of the threads page