Wiped cam lobe mechanical fuel pump

[boarnold]

I have a mid 80s sea ray with mercruiser 3.0. The mechanical fuel pump failed and wiped the lobe off of the cam. I need to install an electric fuel pump. I'm trying to find information on the best way to wire it on. Any help greatly appreciated. Thanks.

 

[matt167]

Needs to be wired through an oil pressure switch. You should also run a wire from the starter to it, so that it bypasses when you turn the key. You’ll find YouTube videos that just say run power, but that’s not legal or smart

 

[Bt Doctur]

on the pressure switch ,wire it thru a cube relay,This will help preventing damage inside the switch

 

[Scott Danforth]

using a 3 contact oil pressure switch. wire the common to the 85 terminal on a VF4 ice cube relay. wire the NC terminal to the R terminal on the starter. wire the NO terminal to the ignition feed (choke or other purple wire).

wire the 86 terminal to ground. wire the 30 terminal to a 10 amp fuse that is connected to the battery
wire the 87 terminal to the fuel pump

make sure the oil pressure switch is about 15psi on rising, and 7 psi on falling. (many NAPA's will have)

 

[Scott06]

In addition to the wiring of the electric fuel pump, I would think you have a lot of metal in the engine from the cam lobe that needs to be cleaned out

 

[Scott Danforth]

In addition to the wiring of the electric fuel pump, I would think you have a lot of metal in the engine from the cam lobe that needs to be cleaned out

agreed. it will be in the pickup strainer and bottom of the pan as well as embedded in the oil pump.

hopefully the oil filter did its job and didnt bypass.

 

[boarnold]

Ok. Thanks for all the help and suggestions. I will give an update after trying some things. I was going to pump the oil out of the dipstick tube to change the oil, but now I'm thinking I should drain by plug to see if I can get more particles out.

 

[Scott06]

Ok. Thanks for all the help and suggestions. I will give an update after trying some things. I was going to pump the oil out of the dipstick tube to change the oil, but now I'm thinking I should drain by plug to see if I can get more particles out.

Definitely drain by plug and flush with kero or diesel. Would put some oil crank it to push remaining crap into filter and cut open filters until it is clean.

I used to jack up the front of my tailer and drop the oil in the bilge and out the drain plug makes a mess but you need to flush the chit out

not sure if you can crank with ignition disabled and filter off and push oil into a bucket to get the chit out?? Not sure if that is stupid , obviously best bet is to jank the engine and clean it out but have seen others on hot rod forums flush and be fine

 

[boarnold]

Scott Danforth - Thank you for your clear directions. I'm looking for a 3 contact oil pressure switch with the psi rising and falling you recommend. I don't want to get the wrong psi switch. Do you have a particular one that you would recommend?

 

[Scott Danforth]

Scott Danforth - Thank you for your clear directions. I'm looking for a 3 contact oil pressure switch with the psi rising and falling you recommend. I don't want to get the wrong psi switch. Do you have a particular one that you would recommend?

go here https://forums.iboats.com/threads/generic-boat-wiring-information-updated-verified.726970/

go to post 12

go to link #3

go to page 15 of the PDF

then go to NAPA and buy it

the one I used was specific for my BBC (covered in post #226 of my build. https://forums.iboats.com/threads/bbc-build-dont-tell-the-admiral.666775/page-12)

 

[tank1949]

I have a mid 80s sea ray with mercruiser 3.0. The mechanical fuel pump failed and wiped the lobe off of the cam. I need to install an electric fuel pump. I'm trying to find information on the best way to wire it on. Any help greatly appreciated. Thanks.

Make sure you use Marine and not automotive.

 

[boarnold]

I'm having trouble locating the oil pressure switch that is needed. I should have prefaced all of this by informing everyone that I have no idea what I'm doing. And I'm am idiot. Does anyone have a part number?

 

[Scott Danforth]

Need to know the port size you are installing it

From there look at what I sent you in post #10

Or at least look up the port size you are installing it in.... Because I'm not going that deep

 

[boarnold]

Scott Danforth - when you said wire the 30 terminal to the battery wire, does that mean where the positive battery cable connects to the starter?

 

[Scott Danforth]

Scott Danforth - when you said wire the 30 terminal to the battery wire, does that mean where the positive battery cable connects to the starter?

Yes

 

[boarnold]

Which terminal is the common? And where do I connect the wire for the oil gauge?

 

[boarnold]

Not sure if the picture came through

 

[Scott Danforth]

The terminals on both the relay and the switch should be labeled

Oil pressure gauges go to a gauge sender

Pics don't currently work

 

[boarnold]

I pulled out the sensor in order to install the 3 contact switch. Is there another port in the mercruiser 3.0 to put the switch? Can I put a T in the port and run the switch and the sender off of the same port?

 

[Scott06]

I pulled out the sensor in order to install the 3 contact switch. Is there another port in the mercruiser 3.0 to put the switch? Can I put a T in the port and run the switch and the sender off of the same port?

Yes you can T the switch and sender to same port . Will likely be 1/8” npt

On later engines like mine this is exactly how mercruiser does it.