U.S. General 93547 User manual

FUEL PUMP AND VFUEL PUMP AND V
FUEL PUMP AND VFUEL PUMP AND V
FUEL PUMP AND VACUUMACUUM
ACUUMACUUM
ACUUM
GAUGE TESTERGAUGE TESTER
GAUGE TESTERGAUGE TESTER
GAUGE TESTER
ASSEMBLY AND OPERATING INSTRUCTIONS
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit ourWebsite at http://www.harborfreight.com
Copyright © 2005 by Harbor Freight Tools®. All rights reserved. No portion of this
manual or any artwork contained herein may be reproduced in any shape or form
without the express written consent of Harbor Freight Tools.
For technical questions and replacement parts, please call 1-800-444-3353
93547
Due to continuing improvements, actual product may
differ slightly from the product described herein.

SKU 93547 For technical questions, please call 1-800-444-3353 Page 2
Specifications
Item Description
Pressure Gauge 4” diameter, gauge scales:
0~28 IN-Hg (0~70 cm-Hg) vacuum;
0~10 PSIG (0~0.7 kg/cm2) pressure
Brass Fittings 1/4”-18 (male) x 1/8” – 27 (female)
1/8”-27 (male) x 7/32” (barbed fitting)
1/8”-27 (female) x 3/8” – 18 (male)
Rubber Hose 13/64” (ID), 23/64” (OD), x 24”, 40 PSI (max)
working pressure
Weight 2 lb.
Save This Manual
You will need the manual for the safety warnings and precautions, assembly
instructions, operating and maintenance procedures, parts list and diagram. Keep
your invoice with this manual. Write the invoice number on the inside of the front
cover. Keep the manual and invoice in a safe and dry place for future reference.
Safety Warnings and Precautions
WARNING:When using tool, basic safety precautions should always be followed
to reduce the risk of personal injury and damage to equipment.
Read all instructions before using this tool!
1. Keep work area clean. Cluttered areas invite injuries.
2. Observe work area conditions. Do not use machines or power tools in
damp or wet locations. Don’t expose to rain. Keep work area well lighted.
3. Keep children away. Children must never be allowed in the work area. Do
not let them handle machines, tools, or extension cords.
4. Store idle equipment. When not in use, tools must be stored in a dry
location to inhibit rust. Always lock up tools and keep out of reach of children.
5. Use the right tool for the job. Do not attempt to force a small tool or
attachment to do the work of a larger industrial tool.There are certain
applications for which this tool was designed. It will do the job better and
more safely at the rate for which it was intended. Do not modify this tool and
do not use this tool for a purpose for which it was not intended.
6. Dress properly. Do not wear loose clothing or jewelry as they can be caught
in moving parts. Protective, electrically nonconductive clothes and nonskid
footwear are recommended when working. Wear restrictive hair covering to
contain long hair.
7. Use eye and ear protection. Always wear ANSI approved impact safety
goggles.Wear ear plugs if working around noisy engines.

SKU 93547 For technical questions, please call 1-800-444-3353 Page 3
8. Do not overreach. Keep proper footing and balance at all times. Do not reach
over or across running machines.
9. Maintain tools with care. Keep tools clean for better and safer performance.
Follow instructions for lubricating and changing accessories.
10. Remove adjusting keys and wrenches. Check that keys and adjusting
wrenches are removed from the tool or engine work surface before operating.
11. Stay alert. Watch what you are doing, use common sense. Do not operate
any tool when you are tired.
12. Check for damaged parts. Before using any tool, any part that appears
damaged should be carefully checked to determine that it will operate
properly and perform its intended function. Check for alignment and binding
of moving parts; any broken parts or mounting fixtures; and any other
condition that may affect proper operation. Any part that is damaged should
be properly repaired or replaced by a qualified technician.
13. Replacement parts and accessories. When servicing, use only identical
replacement parts. Use of any other parts will void the warranty. Only use
accessories intended for use with this tool. Approved accessories are
available from Harbor Freight Tools.
14. Do not operate tool if under the influence of alcohol or drugs. Read
warning labels if taking prescription medicine to determine if your judgment or
reflexes are impaired while taking drugs. If there is any doubt, do not operate
the tool.
15. Avoid working alone. If an accident happens, an assistant can bring help.
Product Specific Safety Precautions
1. Loosen gas cap and relieve fuel pump pressure before testing.
2. Before testing fuel system, verify all connections are tight to eliminate
leaking.
3. Do not change fittings with engine running.
4. Gasoline is highly flammable. Do not smoke, or test near open flames or a
source of electrical sparks.
5. Do not allow gasoline to come in contact with the hot manifolds or other
engine components.
6. Do not drive the vehicle while under test.
7. If portable lighting is required, use only explosion proof drop-light.
8. Before testing, review and follow instructions from the vehicle manufacturer’s
service manual.

SKU 93547 For technical questions, please call 1-800-444-3353 Page 4
9. After testing, turn engine off and depressurize system before removing test
components. Place absorbing cloths around fittings before disconnecting.
Wipe up any spilled fuel. Place cloths in a fireproof container.
10. Clean all testing components of residual fuel before storing.
Warnings
The vehicle engine must never be started in a closed garage, or any other sealed
structure. Carbon monoxide is produced during operation and is deadly in a
closed environment. Early signs of carbon monoxide poisoning resemble the
flu, with headaches, dizziness, or nausea. If you have any of these signs get
fresh air immediately.
The warnings, cautions, and instructions discussed in this instruction manual
cannot cover all possible conditions and situations that may occur. It must be
understood by the operator that common sense and caution are factors which
cannot be built into this product, but must be supplied by the operator.
The brass components of this product contain lead, a chemical known to the
State of California to cause birth defects (or other reproductive harm). (California
Health & Safety Code 25249.5 et seq.)
Unpacking
When unpacking, check to make sure the following parts are included. Refer to the
Parts List at the end of this manual. If any parts are missing or broken, please call
Harbor Freight Tools at the number on the cover of this manual.
Operation
Warning: Before making connections and testing, place a dry chemical (Class
B) fire extinguisher nearby in case of fire.
PrepareVehicle forTesting
1. Park the vehicle in a well ventilated area. If in a garage, park the car so that
the exhaust pipe faces out the garage entrance. Leave garage door open at
all times.
2. Place the transmission in Park/Neutral and set the vehicle emergency brake.

SKU 93547 For technical questions, please call 1-800-444-3353 Page 5
Fuel Pump PressureTest
The components in this Tester Kit enable the testing of the fuel delivery pressure
to the engine.Vacuum / Pressure Gauge (1) connections are made directly to the
pump.
1. Relieve the fuel line pressure from the vehicle fuel system.
Refer to the vehicle manufacturer’s service manual for instruction on
relieving pressure from the fuel line, testing procedures and connection
points, and normal fuel pump pressure readings.
2. Disconnect the pump fuel output line at the pump.
3. Use the various Adapters included and Rubber Hose (2) to connect the
Vacuum / Pressure Gauge (1) directly to the fuel pump.
Use a small amount of pipe compound or teflon tape on the connection
threads to prevent leaks.Tighten using a wrench (not supplied).
Warning: Make sure all connections are tight to avoid fuel leaks.
4. Start the engine and leave at idle speed, and immediately check for fuel
leaks. If fuel leaks are found, turn engine off and fix leaks.
5. Read the pressure off the Vacuum / Pressure Gauge (1). The chart on the
following page gives the approximate correct pressure readings by vehicle.
6. Turn off the engine. The current reading should hold for one or two minutes
before going down to zero.
7. Wrap a cloth around the hose connection point before relieving the pressure
from the fuel line and remove testing components.
8. Reconnect vehicle’s fuel line to the pump.
9. Wipe up any spilled fuel. Dispose of fuel-soaked rags in a fireproof container.
10. Start the engine and immediately check for leaks. If fuel leaks are found, turn
engine off and fix leaks.
11. Clean and store testing components and place in the plastic kit bag.
1~10 PSIG
Testing Range

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Fuel Pump Vacuum Test
1. With the engine off, disconnect the fuel pump inlet line that comes from the
fuel tank. Have a towel ready to wipe up any spilled gasoline.
2. Connect the Vacuum / Pressure Gauge (1) to the fuel pump inlet connector.
Use the Rubber Hose (2) and the various adapters that fit the pump inlet
connector. See photo below. Do not kink Rubber Hose.Do not allow air leaks.
3. Start the engine and immediately view the Vacuum / Pressure Gauge (1).
If the gauge pointer rises to 10 IN/Hg (the red zone), before the pump goes
dry and the engines dies, the fuel pump is working properly.
4. Turn ignition off and reconnect fuel line to the fuel pump.
Testing Carburetor Intake Manifold
1. With the engine off, connect the Vacuum / Pressure Gauge (1) as close as
possible to the intake manifold.
Use the Rubber Hose (2) and the various adapters as needed. See photo
above. Do not kink Rubber Hose. Do not allow air leaks. Engines with two
intake manifolds have to be tested separately.
2. Start the engine and let it idle until the engine temperature reaches its normal
operating temperature.
3. Adjust throttle butterfly valve and set idling speed to get a smooth engine idle.
4. Take vacuum reading from the Vacuum / Pressure Gauge (1).
At idle engine speed, with a properly adjusted carburetor, the gauge pointer
will remain fixed between 17 and 22 IN/Hg (the green zone on the gauge),
19.5, optimum. Readings will vary depending on altitude. Refer to the
vehicle’s service manual for normal and abnormal readings, and adjustment
or repair procedures.
Vacuum Range:
0~28 IN/Hg

SKU 93547 For technical questions, please call 1-800-444-3353 Page 7
Other possible engine problems can be diagnosed as follows:
• When the gauge pressure drops intermittently about 4 IN/Hg, it could be an
indication of sticky valves. Remove the Rubber Hose (2), add a few drops of
penetration oil to the manifold and test again. If the valves stop sticking,
valves need to be cleaned.
• A constant low reading on the gauge could indicate a burnt valve(s).
• If the gauge pointer pulsates rapidly when the engine speed is raised, it could
indicate weak valve springs or poorly seated valves.
• At idle engine speed the gauge pointer pulsates, but at higher speeds the
pointer is steady, this could be an indication of loose valve stem guides.
• When the gauge pointer drops slowly when the engine is speeded up several
times in secession, this could indicate a clogged muffler. An unblocked
muffler will cause the gauge pointer to momentarily drop to zero.
• When the gauge pointer remains at 12 IN/Hg at any engine speed it could
indicate late valve timing.
• Test the choke by closing throttle all the way and starting the engine.The
gauge pointer should immediately rise to 22 IN/Hg (green zone). If the gauge
pointer stays around 3 to 6 IN/Hg this may indicate a burnt riser tube, or the
failure of the throttle valve to close. There could also be air leaks in the intake
manifold system.
Vacuum Testing
1. With the engine off, connect the Vacuum / Pressure Gauge (1) as close as
possible to the intake manifold.
Use the Rubber Hose (2) and the various adapters as needed. See photo on
previous page. Do not kink Rubber Hose. Do not allow air leaks. Engines with
two intake manifolds have to be tested separately.
2. Start the engine and let it idle until the engine temperature reaches its normal
operating temperature.
3. Take vacuum reading from the Vacuum / Pressure Gauge (1).
At idle engine speed, with a properly adjusted carburetor, the gauge pointer
will remain fixed between 17 and 22 IN/Hg (the green zone on the gauge).
A slow, fluctuation between 14 and 22 IN/Hg indicates that the carburetor
needs adjustment, or there are other engine problems. Refer to the vehicle’s
service manual for normal and abnormal readings, and adjustment or repair
procedures.

SKU 93547 For technical questions, please call 1-800-444-3353 Page 8
Parts Diagram
Parts List
Item Description Qty
1. Vacuum / Pressure Gauge 1
2. Rubber Hose, 13/64” (ID), 23/64” (OD) x 24” 1
3. Cone Adapter, Brass 1
4. Plastic Connector 1
5. Adapter, 1/4”-18 (male) x 1/8”-27 (female) 1
6. Adapter, 1/8”-27 (male) x 7/32” (barbed) 1
7. Adapter, 1/8”-27 (female) x 3/8” (male) 1
8. Adapter, T-type, 7/32” (barbed) 1
(1)
(2)
(4)
(3) (6)
(7) (5)
NOTE: Some parts are listed and shown for illustration purposes only and are not
available individually as replacement parts.
(8)
PLEASE READ THE FOLLOWING CAREFULLY
THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE PARTS DIAGRAM
IN THIS MANUAL AS A REFERENCE TOOL ONLY. NEITHER THE MANUFACTURER
NOR DISTRIBUTOR MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND
TO THE BUYER THAT HE OR SHE IS QUALIFIED TO MAKE ANY REPAIRS TO THE
PRODUCT OR THAT HE OR SHE IS QUALIFIED TO REPLACE ANY PARTS OF THE
PRODUCT. IN FACT, THE MANUFACTURER AND/OR DISTRIBUTOR EXPRESSLY
STATES THAT ALL REPAIRS AND PARTS REPLACEMENTS SHOULD BE UNDER-
TAKEN BY CERTIFIED AND LICENSED TECHNICIANS AND NOT BY THE BUYER.THE
BUYER ASSUMES ALL RISK AND LIABILITY ARISING OUT OF HIS OR HER REPAIRS
TO THE ORIGINAL PRODUCT OR REPLACEMENT PARTS THERETO, OR ARISING
OUT OF HIS OR HER INSTALLATION OF REPLACEMENT PARTS THERETO.
REV 01/06