ENGINE - 2GR-FE ENGINE
285EG18
Secondary
Timing
ChainExhaust Camshaft Intake CamshaftsExhaust Camshaft
Roller Rocker Arm
Va l v e S p r i n g
Retainer
Va l v e S p r i n g
Hydraulic
Lash Adjuster
Va l v e G u i d e
Bush Va l v e S p r i n g
Sheet
Va l v e
Secondary Timing
Chain Primary
Timing
Chain EG-80
VA LV E M E C H A N I S M
1. General
Each cylinder of this engine has 2 intake valves and 2 exhaust valves. Intake and exhaust efficiency is
increased due to the larger total port areas.
This engine uses roller rocker arms with built-in needle bearings. This reduces the friction that occurs
between the cams and the areas (roller rocker arms) that push the valves down, thus improving fuel
economy.
A hydraulic lash adjuster, which maintains a constant zero valve clearance through the use of oil pressure
and spring force, is used.
The intake camshafts are driven by the crankshaft via the primary timing chain. The exhaust camshafts
are driven by the intake camshaft of the respective bank via the secondary timing chain.
This engine uses a Dual VVT-i (Variable Valve Timing-intelligent) system which controls the intake and
exhaust camshafts to provide optimal valve timing according to driving conditions. With this adoption,
lower fuel consumption, higher engine performance, and fewer exhaust emissions have been achieved.
For details of Dual VVT-i control, see page EG-120.
ENGINE - 2GR-FE ENGINE
238EG70
Synchronous Injection
IgnitionNon-synchronous Injection
Crankshaft Angle # 1
# 2
# 3
# 4
# 5
# 6
0
120240360480600720
Independent InjectionEG-117
Air-fuel Ratio Sensor and Heated Oxygen Sensor
The planar type air-fuel ratio sensor and the cup type heated oxygen sensor are used. For details, see page
EG-37.
6. SFI (Sequential Multiport Fuel Injection) System
An L-type SFI system directly detects the intake air mass with a hot wire type mass air flow meter.
An independent injection system (in which fuel is injected once into each cylinder for each two revolution
of the crankshaft) is used.
There are two (synchronous and non-synchronous) injections:
a) The synchronous injection in which corrections based on the signals from the sensors are added to the
basic injection time so that injection occurs always at the same position.
b) The non-synchronous injection in which injection is effected by detecting the requests from the signals
of the sensors regardless of the crankshaft angle.
Furthermore, to protect the engine and achieve lower fuel consumption, the system uses a fuel cutoff in
which the injection of fuel is stopped temporarily in accordance with the driving conditions.
This system performs group injection when the engine coolant temperature is extremely low and the
engine is operating at a low speed.
7. ESA (Electronic Spark Advance) System
This system selects the optimal ignition timing in accordance with the signals received from the sensors and
sends the (IGT) ignition signal to the igniter.
