4
Operating Instructions and Parts Manual
27167
10/18
2018 OEM
®
FUEL PRESSURE
TEST KIT
PRE-TEST CHECKS
1. Read Safety Precautions.
2. Do a thorough visual and “hands-on” inspection of the
engine and fuel system. Look for loose or cracked
electrical wiring, battery cables, ignition wires and fuel
or vacuum lines.
3. Verify that the fuel tank has an adequate supply of fuel
and the battery is fully charged.
4. Verify that the inertia switch on certain Ford/Lincoln/
Mercury vehicles has not been tripped. (The inertia
switch is usually located in the trunk.)
5. Verify that all fuel system fuses are good.
6. Verify that fuel vapor recovery system and gas cap are in
good condition.
7. Verify that manifold vacuum is within manufacturers’
specification. (Typically 18-20 inches at idle)
8. Look for fuel leaks and immediately clean up any spilled
fuel.
9. If engine will not start, check ignition system for spark.
If no ignition spark is present, refer to vehicle service
manual for No Start Diagnostics.
10. Inspect the wire harnesses and electrical connectors
for damaged or corroded parts.
11. Check other electrical systems including ignition and
car computer system.
FUEL PRESSURE TESTING PROCEDURES
This test procedure explains how to make fuel pressure
measurements on vehicles while the ignition key is on and
while engine is at idle. The procedure also explains the
safest way to connect and disconnect fuel pressure tester
kit from vehicles. If fuel pressure readings measured in
this test procedure are not within vehicles manufacturer’s
specification, then use vehicle service manual along
with fuel pressure tester kit to service problem. This
test procedure does not contain any vehicle specific
diagnostics.
1. Read all Safety Precautions and Pretesting Checks.
2. Apply a lightweight household oil to rubber “0” rings or
test adapters.
3. Turn Ignition Key OFF.
4. Install Gauge.
FOR CHRYSLER/GM VEHICLES WITH TEST
PORT:
• Remove Test Cap.
• Screw Chrysler/GM test port adapter to fuel rail test port
until finger tight.
NOTE:
Always wrap a shop rag around fuel rail test port
when attaching test port adapters. This is a precaution
in case a small amount of fuel leaks out while attaching
adapters.
FOR FORD/LINCOLN/MERCURY VEHICLES
WITH TEST PORT:
• Remove Test Cap.
• Screw Ford test port adapter to fuel rail test port until
finger tight.
• Screw Chrysler/GM test port adapter to Ford test port
adapter until finger tight.
FOR GM TBI VEHICLES WITHOUT A TEST PORT:
• Disable fuel pump(s) and relieve fuel system pressure by
following instructions in vehicle service manual.
WARNING: Some vehicles may have more than one fuel
pump. Failure to deactivate all fuel pumps can result
in spilled fuel, fire, or other hazardous conditions that
could cause vehicle damage personal injury, or death.
• Disconnect the fuel line at location described in vehicle
service manual using shop towels to catch any released
fuel.
• Attach GM TBI test adapter, and then attach fuel line to
adapter. Tighten all fittings finger tight and then tighten
gently 1/2 turn with wrenches.
