VO filter restriction set-up

Anything related to biodiesel/biofuels, questions, answers, technical information for all VW Diesel Engines should go here.

Moderator: Fatmobile

Post Reply
87wolfsburgedition
Glow Plug
Posts: 7
Joined: Sat Apr 21, 2012 11:33 am

VO filter restriction set-up

Post 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.
Fatmobile
Global Moderator
Posts: 7444
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa
Contact:

Re: VO filter restriction set-up

Post 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
'91 Golf gasser converted to turbo diesel.
'83 Rabbit gasser, converted to diesel, then converted to run on vegetable oil.
2, '84 GTI projects cars
87wolfsburgedition
Glow Plug
Posts: 7
Joined: Sat Apr 21, 2012 11:33 am

Re: VO filter restriction set-up

Post 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?
Fatmobile
Global Moderator
Posts: 7444
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa
Contact:

Re: VO filter restriction set-up

Post 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.
'91 Golf gasser converted to turbo diesel.
'83 Rabbit gasser, converted to diesel, then converted to run on vegetable oil.
2, '84 GTI projects cars
surferdean
Glow Plug
Posts: 4
Joined: Sat May 03, 2014 4:11 pm
Location: Santa Barbara, CA, USA

Re: VO filter restriction set-up

Post 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.
1982 VW diesel 1.6L NA caddy pickup
328,000 + miles daily driver
7 yr. 52,000 mi. on WVO
Fatmobile
Global Moderator
Posts: 7444
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa
Contact:

Re: VO filter restriction set-up

Post 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.
'91 Golf gasser converted to turbo diesel.
'83 Rabbit gasser, converted to diesel, then converted to run on vegetable oil.
2, '84 GTI projects cars
surferdean
Glow Plug
Posts: 4
Joined: Sat May 03, 2014 4:11 pm
Location: Santa Barbara, CA, USA

Re: VO filter restriction set-up

Post 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.
1982 VW diesel 1.6L NA caddy pickup
328,000 + miles daily driver
7 yr. 52,000 mi. on WVO
Post Reply