vro2 help

cdoliver

Petty Officer 1st Class
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Mar 18, 2008
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211
I have a motor that I'm slowly putting together (Winter project). It's a 1989 150 crossflow. I bought a used pump on ebay from a scrapped motor. Supposedly it works. I can't make it work... Is there any way to test this pump? Also, if it's not working, should I buy the rebuild kit for the vro or just go with the old two pump system? What would be the least expensive way to go? I don't intend on using the oil injection. Thank you
 

ezeke

Supreme Mariner
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Sep 19, 2003
Messages
12,532
Re: vro2 help

The VRO2 pump that came with the motor can be rebuilt on the gasoline side only and the electronics cannot be rebuilt.

As a premix pump, the VRO2 is more powerful than the two lift pump system. You don't need the electronics for premix.

The rebuild kit for the gasoline side of the pump is actually two kits sold as a package (0435921+0436095) You can get the kits from Bill Kelly at maxrules.com.

He has the instructions and the test chart set up on his website. Go to this link and scroll down to "ALL .....": http://www.maxrules.com/fixomcvro.html

You may also want to read the following thread: http://continuouswave.com/whaler/reference/VRO.html
 

cdoliver

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Mar 18, 2008
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211
Re: vro2 help

Thank you ezeke.

I would like to use the vro2 pump being that it is better. I don't mind spending the $90 for the kit. However, I have also read that sometimes the kit doesn't repair the problem. Other parts (checkvalves and such) aren't replaced in the kit. What is the likelihood of this happening? Also, I forgot to mention that the fuel inlet is missing a part. There is just a hole there. there is nothing to slide the fuel hose on. (I fabricated something temporary for testing) Is there a part to replace this or is this pump useless? It doesn't look like anything is broken, just missing. A fitting pressed in there? Thanks again
 

ezeke

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Sep 19, 2003
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Re: vro2 help

Building the two lift pump system with OEM parts will cost around 200.00 with the hoses and clamps.

No guarantees on your pumps, you know better than anyone here what condition they are in. I don't know of any reliable way to rebuild the hose nipple, but maybe someone else has done it.

I rebuilt the same VRO2 pump myself without a problem. Mine is original 1988 and is still going strong as a premix pump.
 

tashasdaddy

Honorary Moderator Emeritus
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Nov 11, 2005
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51,019
Re: vro2 help

if i wanted to use a mix system, i would go with the new OMS pump, far more reliable than either of the VRO pumps.
 

cdoliver

Petty Officer 1st Class
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Mar 18, 2008
Messages
211
Re: vro2 help

one last question.

Are the oms2 pumps all the same for v4/ v6's? for example, Will a v4 looper vro2 pump from the same year work on this v6? Also, what is the purpose of the pulse limiter. I don't have one.
 

ezeke

Supreme Mariner
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Sep 19, 2003
Messages
12,532
Re: vro2 help

The pulse limiter is a check valve in the pulse line running from the engine to the fuel pump. The pulse created by one of the cylinders drives the fuel pump.

The pulse limiter stops the pulse at a preset level to protect the pump. It takes a fairly good amount of pressure to close it. If the pulse limiter on your engine is black, it should have been replaced with one that is blue and gold.

The VRO2 pumps were discontinued in favor of the OMS pumps after 1992. VRO2 and OMS pumps for V4 and V6 motors are the same.

The V6 motors also had a separate vacuum switch, used for a fuel obstruction alarm, that the V4 engine did not have. It is mounted close to the pump but is not part of it and it has its own wiring.
 

cdoliver

Petty Officer 1st Class
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Mar 18, 2008
Messages
211
Re: vro2 help

Not having a pulse limiter wouldn't cause my vro2 pump to not work? Thank you all, again
 

ezeke

Supreme Mariner
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Sep 19, 2003
Messages
12,532
Re: vro2 help

Not having the pulse limiter will not keep the pumps from working, but could enable a backfire to damage the pump.
 
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