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Plug vacuum hose and note fuel gauge reading. Gauge reading should be 36-41 psi. Pressure should have risen
slightly when vacuum hose was disconnected from pressure regulator.
9.2.3
If pressure is higher than specified, inspect for pinched or clogged fuel return line between fuel rail and fuel tank. If no problem is found
in fuel line, replace pressure regulator.
9.2.4
If pressure is lower than specified, inspect for plugged fuel filter. If filter is not plugged, lightly pinch off fuel return line. If fuel pressure
does not rise, replace fuel pump. If fuel pressure does rise, replace pressure regulator.
10. FUEL PRESSURE TEST
TOYOTA (TYPICAL)
CAUTION: High fuel pressure may be present in fuel lines and component parts. Relieve pressure before attempting to open
system for testing or component replacement. DO NOT allow fuel to run onto engine or electrical parts, or allow an open flame
in area while testing.
10.1.
FUEL PUMP QUICK TEST
10.1.1.
Turn ignition on, with engine off. On all except Van, place jumper wire across"+B" and "FP" terminals of engine check connector in
engine compartment. On Van, place jumper wire across 2-wire fuel pump check connector (White/Black and Green wires) located
under driver's seat.
10.1.2.
On all models, listen for fuel pump running sound. Feel for pressure in fuel line between filter and fuel rail. Turn ignition off. Remove
jumper wire. If fuel pump sound was present and fuel hose showed pressure, go to FUEL SYSTEM PRESSURE TEST.
10.1.3.
If no pressure or fuel pump sound was present, on all except Van, connect a jumper wire from battery sources to "FP" terminal of
engine check connector.
10.1.4.
On all except Van, if fuel pump does not run or no pressure is felt in line, check for defective fuel pump. Check for open circuit between
engine check connect and fuel pump or poor fuel pump ground.
NOTE:
All models use in-tank fuel pump. Fuel pump contains internal relief valve and check valve.
If fuel pump ran after battery source as connected to "FP" terminal in step 3, check EFI main relay and relating wiring. Also check
"EFI"and "IGN"fuses.
10.2.
FUEL SYSTEM PRESSURE TEST
NOTE:
Before testing fuel pressure, check all fuel delivery and return lines for leaks.
Ensure battery is fully charged. Turn ignition off. On all except Pickup and 4Runner with 3VZ-E, place container or shop towel under
cold start injector. Slowly loosen cold start injector union bolt to relieve fuel pressure. Remove union bolt and 2 gaskets.
Install fuel pressure gauge to the cold start injector delivery pipe. Wipe off excess fuel.
10.2.1.
On all except Van, install jumper wire between engine check connector "FP"and"B" pins. On Van, place jumper wire across 2-wire fuel
pump check connector (White/Black and Green wires).
10.2.2.
On all models, turn ignition on, with engine off. Measure fuel pressure. Fuel pressure should be same as regulated pressure.
10.2.3.
If fuel pressure is high, replace the fuel pressure regulator. If fuel pressure is low, check the following:
10.2.4.
Fuel hoses and connections, Fuel filter, Fuel pump, Fuel pressure regulator.
10.2.5.
Remove jumper wire installed in step 3. Start engine and run for 2 minutes. Disconnect vacuum sensing hose from fuel pressure
regulator and plug hose end. Fuel pressure regulator is mounted on fuel rail.
NOTE:
On Celica (3S-GTE), Corolla (4A-GE), MR2, PickupMRunner, and Van it is necessary to allow engine to idle for 2 minutes to
stabilize fuel pressure. These models are equipped with a fuel pressure-up system which temporarily increases fuel pressure after a
hot start.
10.2.6.
Measure regulated fuel pressure at idle speed.
10.2.7.
With engine still idling, reconnect fuel pressure regulator sensing hose. Measure regulated pressure at idle.
10.2.8.
If regulated pressure was not specified, check vacuum sensing hose fuel pressure regulator. On models so equipped, check fuel
pressure-up system.
10.2.9.
Stop engine. Note fuel pressure. Leave fuel pressure gauge attached to engine for at least 5 minutes.
10.2.10. Residual fuel pressure after 5 minutes should be at least 21 psi (1.5 kg/cm²). If pressure is not as specified check for leaking injectors,
fuel pressure regulator or bad check valve in fuel pump.
10.2.11. Relieve fuel system pressure. Remove fuel pressure gauge. Reconnect cold start injector. Run engine and check for fuel leaks.
11. FUEL PRESSURE TEST
BOSCH (TYPICAL)
CAUTION: High fuel pressure may be present in fuel lines and component parts. Relieve pressure before attempting to open
system for testing or component replacement. DO NOT allow fuel to run onto engine or electrical parts, or allow an open flame
in area while testing fuel system components.
11.1.
FUEL PUMP CIRCUIT
11.1.1.
Remove fuel tank cap.
11.1.2.
Turn ignition on and listen for fuel pump operating sound for approximately 2 seconds. If there is not sound, check fuse, fuel pump
relay, fuel pump and all electrical connections.
11.2.
VISUAL CHECK
11.2.1.
Remove air cleaner and check for any visible fuel leaks.
11.2.2.
Push airflow sensor plate down manually.
11.2.3.
Uniform resistance should be felt throughout travel after slight amount of free travel. No binding should be felt when sensor plate is
released.
11.2.4.
Upward movement of sensor plate should be slow with slight resistance from control piston adjusting lever. No binding should be felt.
11.2.5.
Push airflow sensor plate down and hold briefly. Slight fuel seepage past control is acceptable.
12. FUEL PRESSURE TEST
CIS (TYPICAL)
NOTE: Control pressure is measured with the valve open and system pressure is measured with valve closed.
12.2.1.
Install Fuel Pressure Gauge and Adaptor between the fuel distributor test port and cold start valve. Ensure control lever is in the closed
position. Bleed excess air from system by cycling control valve with gauge upside down.
12.2.2.
Using a jumper wire, connect terminals No. 30 and 87 on fuel pump relay. Open fuel pressure gauge control lever. Fuel pressure
should be within specification If fuel pressure is low, perform fuel volume check. If fuel volume is okay, replace fuel pressure regulator.
12.2.3.
If fuel pressure is above specification, remove return hose from pressure regulator and repeat test.
© Jack Sealey Limited
Original Language Version
VSE210 Issue 2 (HF)
08/09/21
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