Lexus SC300 / Lexus SC400. Manual — part 600

(j)

Turn the ignition switch ON.

(k) Measure the fuel pressure.

Fuel pressure: 265–304 kPa

(2.7–3.1 kgf/cm

2

, 38–44 psi)

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

•

Fuel hoses and connections

•

Fuel pump

•

Fuel filter

•

Fuel pressure regulator

(l)

Remove SST from the check connector.

SST 09843–18020

(m) Start the engine.
(n) Disconnect the vacuum sensing hose from the fuel

pressure regulator, and plug the hose end.

(o) Measure the fuel pressure at idling.

Fuel pressure: 265–304 kPa

(2.7–3.1 kgf/cm

2

, 38–44 psi)

(p) Reconnect the vacuum sensing hose to the fuel

pressure regulator.

(q) Measure the fuel pressure at idling.

Fuel pressure: 196–235 kPa

(2.0–2.4 kgf/cm

2

, 28–34 psi)

If pressure is not as specified, check the vacuum sensing
hose and fuel pressure regulator.
(r) Stop the engine. Check that the fuel pressure remains

147 kPa (1.5 kgf/cm

2

, 21 psi) or more for 5 minutes after

the engine is turned off.

If pressure is not as specified, check the fuel pump, pressure
regulator and/or injectors.
(s) After checking fuel pressure, disconnect the battery

negative (–) cable and carefully remove the SST to
prevent gasoline from splashing.

SST 09268–45012
(t) Connect the rear fuel pipe to the delivery pipe with two

new gaskets and the union bolt.

Torque: 39 N

⋅

m (400 kgf

⋅

cm, 29 ft

⋅

lbf)

(u) (Exc. USA spec.)

Reinstall the filter to the VSV.

(v) Reconnect the cable to the negative (–) terminal of the

battery.

(w) Check for fuel leaks. (See page

FI–16

)

FI–19

EFI SYSTEM – Fuel System (Fuel Pump)

COMPONENTS FOR REMOVAL AND
INSTALLATION

FI–20

EFI SYSTEM – Fuel System (Fuel Pump)

REMOVAL OF FUEL PUMP

(See Components on page

FI–20

)

CAUTION: Do not smoke or work near an open flame
when working on the fuel pump.

1.

DISCONNECT CABLE FROM NEGATIVE TERMINAL OF
BATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ”LOCK” position and negative (–) terminal
cable is disconnected from the battery.

2.

REMOVE LUGGAGE COMPARTMENT FLOOR MAT

3. REMOVE

SPARE

TIRE

4.

REMOVE LUGGAGE COMPARTMENT TRIM COVER

5.

DISCONNECT FUEL PUMP CONNECTOR

6.

REMOVE SEAT CUSHION AND BACK

7. REMOVE

PARTITION

COVER

Using a scraper, pry out the partition cover.

8.

REMOVE FUEL PUMP
(a) Remove the eight bolts, and disconnect the fuel pump

set plate from the fuel tank.

(b) Remove the three nuts, and disconnect the fuel pump

bracket from the fuel tank.

(c) Disconnect the fuel hose from the fuel pump bracket,

and remove the fuel pump, bracket and set plate
assembly.

FI–21

EFI SYSTEM – Fuel System (Fuel Pump)

INSPECTION OF FUEL PUMP

1.

INSPECT FUEL PUMP RESISTANCE
Using an ohmmeter, measure the resistance between the ter-
minals.

Resistance: 0.2–3.0

If the resistance is not as specified, replace the fuel pump
and/or set plate.

2.

INSPECT FUEL PUMP OPERATION
Connect the positive (+) lead from the battery to terminal 1 of
the connector, and the negative (–) lead to terminal 2. Check
that the fuel pump operates.
NOTICE:

•

These tests must be performed quickly (within 10

seconds) to prevent the coil from burning out.

•

Keep the fuel pump as far away from the battery as

possible.

•

Always perform switching at the battery side.

If operation is not as specified, replace the fuel pump and/or
set plate.

COMPONENTS FOR DISASSEMBLY AND
ASSEMBLY

FI–22

EFI SYSTEM – Fuel System (Fuel Pump)