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02/23/03*
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 Note:
At one time you could tell the Alternator Fuel Pump from the Generator
Pump as the Alt. pump was Tilted Slightly but
not any more. The Alternators Fuel pumps have the contact lever
protruding out the bottom of the pump about 3/16" and the push rod
is 3 7/8" long. -- As you can see the Tilted Generator pump on the
left made for the Generator engine has the pivot pin higher up in the
pump body, All Generator pumps uses the 4 3/16" long rod. Use the
wrong rod and you can destroy the pump.
Fuel Pressure
VW states the fuel pressure should be 2.8 - 3.5 psi at 3400 rpm.
Other manuals state 4 psi and 400cc/minute at 3800 rpm.
The cam on the lower part of the distributor drive lifts the fuel pump
rod, which has a 0.160 inch stroke.
The distributor drive seldom causes any problems but there have been
some soft fuel pump rods produced.
If you put a file to the fuel pump rods pointed end and nothing happens
its OK but if the file can cut it then you have a soft rod and it
should be replaced.
One other thing that can effect fuel pressure is adjusting the
distributor drive end play.
This changes the distance the fuel pump rod extends out of the phenolic
base.
The only way to accurately check the fuel pressure is "T" a
gage into the line.
The pressure can be adjusted by adding gaskets under the fuel pump
phenolic block to decrease pressure or by removing a gasket to increase
the pressure.
The fuel pump block can be shortened by sanding the top surface but this
is not normally needed.
Be aware when you reduce the pump pressure by adding gaskets you will
also be reducing the volume.
With Weber or Delorto carbs its best to use a adjustable Fuel Pressure
Regulator (#V105622) these big carbs are much more sensitive to fuel
pressure then stock carbs.
Generator fuel pumps use the 4.18" long
rod and the alternator pump rod is 3.92" long.
Don't get them mixed up as you can ruin a new fuel pump with two turns
of the crank.
For a simple test start with a Fire Extinguisher in one hand,
then pull the fuel line off the carb. Have someone hit the
starter. The fuel should squirt out 2 to 5 feet.
VW fuel pump delivers 400 cc/min at 3400 rpm and 3.0-5.0 psi
If it only pumps a stream out 6" to 8" then the pump is bad or
there is some restriction in the fuel supply line.
To test for restrictions, fill the tank fairly full, disconnect the fuel
line from the fuel pump and extend the fuel line so the fuel can drain
into a large gas can.
Check the size of the stream coming out of the hose when you start and
then again after several gallons have been drained out.
If the stream gets smaller then its time to check the tank vent or the
fuel screen in the bottom of the tank for restrictions.
Some owners replace the stock pump with an electric one (#V127001) but
remember the elec. pump keeps on pumping as long as the switch is
on.
If you roll your buggy the electric pump keeps on delivering fuel even
when the motor stops.
You can install an oil pressure switch that cuts the power when the oil
pressure is low.
You might want to buy a spare pump as some of the stock ones only last a
couple hundred thousand miles. :-)
Fuel Pump for Generator Engines -> Order
Fuel Pump for Alternator Engines ->
Order
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Victor Comp. Products Inc.
**--Vic's--** Phone 816-650-3535 • 230 S Hudson St., Buckner,
Missouri, 64016, US
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