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Fuel pressure tests for bosch (typical), Fuel pressure tests for l-jetronic (typical) – Sealey VSE210 User Manual

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10. FUEL PRESSURE TESTS FOR TOYOTA (TYPICAL)

12. FUEL PRESSURE TESTS FOR CIS (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.

10.1.5 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.

10.2.1 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.

10.2.2 Install fuel pressure gauge to the cold start injector delivery pipe. Wipe off excess fuel.

10.2.3 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).

10.2.4 On all models, turn ignition on, with engine off. Measure fuel pressure. Fuel pressure should be same as regulated pressure.

10.2.5 If fuel pressure is high, replace the fuel pressure regulator. If fuel pressure is low, check the following:

Fuel hoses and connections, Fuel filter, Fuel pump, Fuel pressure regulator.

10.2.6 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.

10.2.7 Measure regulated fuel pressure at idle speed.

10.2.8 With engine still idling, reconnect fuel pressure regulator sensing hose. Measure regulated pressure at idle.

10.2.9 If regulated pressure was not specified, check vacuum sensing hose fuel pressure regulator. On models so equipped, check fuel

pressure-up system.

10.2.10 Stop engine. Note fuel pressure. Leave fuel pressure gauge attached to engine for at least 5 minutes.

10.2.11 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.

10.2.12 Relieve fuel system pressure. Remove fuel pressure gauge. Reconnect cold start injector. Run engine and check for fuel leaks.

NOTE: Control pressure is measured with the valve open and system pressure is measured with valve closed.

12.1.1 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.

12.1.2 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.

12.1.3 If fuel pressure is above specification, remove return hose from pressure regulator and repeat test. Fuel pressure should be within

specification. If okay, check for restricted fuel return line. If pressure is incorrect, replace fuel pressure regulator.

11. FUEL PRESSURE TESTS FOR 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.

Push airflow sensor plate down and hold briefly. Slight fuel seepage past control is acceptable.

13. FUEL PRESSURE TESTS FOR L-JETRONIC (TYPICAL)

13.1.1 Install Fuel Pressure Gauge at fuel supply hose 3-way "T" connector.

13.1.2 Turn ignition on.

13.1.3 With fuel pump operating,minimum pressure should be within specification. if fuel pressure is incorrect, inspect for restricted fuel lines,

defective fuel pump or weak pressure regulator.

VSE210 - 1 - 211204