Replacing VRO 3 wire with a 4 wire pump

[Branch Creek]

I’m sure it’s in here somewhere but I need some assistance. I have a 1987 Evinrude 90hp that is in bad need of a new fuel pump. I bought a new VRO 4 wire pump. My engine has the 3 wire harness. Question time: 1) Where does the 4th wire go? 2) Since the old pump had the oil side bypassed, how do I know the warning system functions? If I continue with the oil side bypassed, I still want to make sure the warning system works. I’ve had this motor for a long time but haven’t worried about it much but I want to keep this engine running as long as I can. Still saving for the e-tec I want. 3) The new pump came with a plug that fits the pump but only has a purple wire attached. Where does this wire go? I’ve looked for diagrams online but can find any. FYI: not a stranger to wiring and working on this engine.

thanks in advance

 

[racerone]

??----If you are premixing you do not need the wires hooked up at all !

 

[Branch Creek]

Yeah. I just want to make sure I’m getting the most out of motor. From what I can tell, the overheat alarm is not hooked up without it being plugged into the pump. Could be wrong though.

 

[racerone]

Test the overheat alarm.----See if it works without the VRO warning module plugged in !!

 

[achris]

VRO is the biggest destroyer of OMC engines. The best thing you can do to make sure the engine doesn't die prematurely is to ditch the VRO altogether, and fit a normal fuel pump and run premix. When I had my shop, that was the job on every second OMC outboard. (waiting for the OMC fanboys to jump all over that... )

As for the overheat alarm, just hook the wire form the sensor directly to the alarm wire that comes from the control box. The overheat switch is designed to handle the current (which isn't much anyway) of the alarm horn.

Chris.........

 

[flyingscott]

Why not buy the oil tank and use the pump for.oil injection? If.you paid that much for the pump why not use it. To convert to a 4 wire pump there is an adaptor you need. If you do not plan on using the oil injection side just don't plug it in. For reference there is a fuel pump only VRO available.

 

[racerone]

On an 87 model you would just buy the $100 pump that fits over a pulse port on intake manifold.-----Remove plug and install the pump with 2 screws and a gasket.-----That pump would have a fuel in port on filter cap and a fuel out port.-----It would work faithfully for 20 years.----How did you determine that this motor was " in bad need of a fuel pump " ?-----What trouble shooting was done ?

 

[Branch Creek]

Leaked fuel like crazy out of the oil side. I stopped the leak several times but it kept getting worse. Sometimes it was sucking air into the fuel. I have already bought a replacement VRO pump (under $200) and have installed it. I’m on the fence of hooking up the oil side or keeping it bypassed. The new pump is a 4 wire and I don’t know where the 4th wire (purple) goes.

 

[Branch Creek]

Flyingscott,

I’d like to use the oil side. I have a new tank coming; mainly for when I get the money to buy the e-tec motor one day. I am searching for the oil tank wires that were disconnected years ago but haven’t found them yet. The main issue is I find anything to show where the 4th wire goes. It’s the purple one in the middle of the 3 original wires.

 

[dingbat]

The purple wire goes to a switched 12v source.


5007423 replaces 3 wire pumps and includes adapter to change to 4 wires

 

[flyingscott]

Who made the pump that it only cost $200? Never seen one that low before.

 

[Branch Creek]

I ordered it online from The Rop Shop. Thanks for all the help folks. Now I just have to make up my mind if I want to keep mixing or use the VRO

 

[flyingscott]

keep mixing.

 

[oldboat1]

Do a search here on iBoats for 3 to 4 wire VRO conversions (e.g., https://forums.iboats.com/forum/engi...-vro-to-4-wire ).

 

[Branch Creek]

I bookmarked that post, thanks oldboat. I probably will keep mixing but I’d like to make sure I get everything connected properly for the tank. The shop I’m getting the e-tec from will not mount it unless I have a oil reservoir installed and working. My plan is to buy the new motor in 2021.

 

[flyingscott]

I wouldn't trust that pump to move water out of my bilge. It looks like a chinese knock off and i would not trust it as an oil pump. Keep.premixing.Your new E-Tec should come with a tank.