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VO filter restriction set-up

Posted: Sun Apr 29, 2012 7:03 pm
by 87wolfsburgedition
Is anybody using a restriction gauge on their dash? The only ones I can find under $200 are mechanical gauges, but I would like to install one in my Vanagon conversion and go with electrical with a sending unit. Anybody doing this?

In my RV I have a filter restriction gauge, but it is mechanical, so running the tubing 35ft to the front dash isn't feasible. So I installed it at the filter.

Re: VO filter restriction set-up

Posted: Sun Apr 29, 2012 11:35 pm
by Fatmobile
A search using vacuum gauge will give you some info.
Vacuum gauges can be found for pretty cheap on ebay.

I know you don't want to run a hose all the way to the front,.. and the hose would fill with fuel.

Sooo I don't know if you would be happy with an idiot light.
That could be run with a wire.

aaand they are dirt cheap, adjustable and readily available;
in gasser rabbits, in the vacuum line going to the distributor.

They can be used to run a light or buzzer,.. use a couple of them at different settings.
Image

Re: VO filter restriction set-up

Posted: Mon Apr 30, 2012 12:11 am
by 87wolfsburgedition
Fatmobile wrote: Sooo I don't know if you would be happy with an idiot light.
That could be run with a wire.

aaand they are dirt cheap, adjustable and readily available;
in gasser rabbits, in the vacuum line going to the distributor.

They can be used to run a light or buzzer,.. use a couple of them at different settings.
Image
So how does it work? Does it just send a signal to turn the light on when it hits a certain PSI / vacuum pressure?

Re: VO filter restriction set-up

Posted: Tue May 01, 2012 2:17 am
by Fatmobile
It's a switch so it goes in series with a light or buzzer.
12v>switch>light/buzzer>ground.
The screw in the middle adjusts the trip point.

Re: VO filter restriction set-up

Posted: Sat May 03, 2014 7:13 pm
by surferdean
I suggest using small diameter polyurethane tubing, almost as easy as running a wire. Then, just connect it to an ordinary auto vacuum gage costing about $20. Polyurethane is extremely tough, will not collapse with a vacuum, WVO does not hurt it and it is readily available at reasonable cost.

Re: VO filter restriction set-up

Posted: Sat May 03, 2014 9:18 pm
by Fatmobile
I once collapsed 3/8" PEX tubing with injection pump vacuum. Wasn't paying attention after switching when it was too cold.
Sucked it flat.
I do use 1/8" urethane tube to my vacuum gauge without a problem. If I did try to run it all the way to the front of a vanagon for a vacuum gauge it would gather fuel in all the low spots. I'd also suggest pieces of rubber tube over it for places where it rubs under the vehicle. Not real problems but I'd rather use wire for a long run like that.

Re: VO filter restriction set-up

Posted: Sun May 04, 2014 10:22 am
by surferdean
My WVO vacuum gauge system is now 7 years old. I used 1/4 inch clear urethane tubing to the gauge. It is about 5 feet long going from injector pump to dash board. Being clear tubing, I can see WVO all the way up to, and it must be inside, the vacuum gauge. The gauge, which is a cheap combination auto manifold vacuum/fuel pressure gauge, continues to work fine.

The vacuum part of the gauge reads in inches of mercury. On a cold morning it will usually pull 5 inches then go down to 1 inch pretty quick. I use a Racor 10 micron filter. It will last about 2 years. I changed it about a month ago when the vacuum would not go below 10 inches even when hot. An inch of mercury is about 1/2 psi.