2001 TOYOTA PRIUS Combustion

ENGINE ± 1NZ-FXE ENGINE
182EG03
N.m
120
110
100
90
80
Torque
1000 2000 3000 4000 5000
Engine Speed (rpm)kW
60
50
40
30
20
10
Output
0 44

Engine Specifications 
Engine Type1NZ-FXE1NZ-FE (ECHO)
No. of Cyls. & Arrangement4-Cylinder, In-line

Valve Mechanism16 Valve DOHC, Chain Drive

Combustion ChamberPentroof Type

ManifoldsCross-Flow

Fuel SystemSFI

Displacement cm3 (cu. in.)1497 (91.3)

Bore x Stroke mm (in.)75.0 x 84.7 (2.95 x 3.33)

Compression Ratio13.0 : 110.5 : 1
Max. Output [SAE-NET]52 kW @ 4500 rpm
70 HP @ 4500 rpm81 kW @ 6000 rpm
108 HP @ 6000 rpm
Max. Torque [SAE-NET]111 N.m @ 4200 rpm
82 lb-ft @ 4200 rpm142 N.m @ 4200 rpm
105 lb-ft @ 4200 rpm
IntakeOpen18
±25 BTDC±7
53 BTDC
Valve
IntakeClose72
115 ABDC52
±8 ABDCValve
Timing
ExhaustOpen34 BBDC42 BBDCg
ExhaustClose2 AT D C

Fuel Octane Number RON91 or more

Oil GradeAPI SJ EC or ILSAC


Performance Curve 

ENGINE ± 1NZ-FXE ENGINE
182EG04
Valve Angle 33.5
Water Jacket 46
ENGINE PROPER
1. Cylinder Head

The angle of the intake and exhaust valves is narrowed and set at 33.5 to permit a compact cylinder head.

As a result of installing the injector in the intake port of the cylinder head, the contact of the fuel against
the intake port wall has been minimized and fuel economy has been improved.

A water jacket has been provided between the exhaust port and the spark plug boss in order to maintain
the combustion chamber wall temperature uniform, thus improving the cooling performance of the com-
bustion chamber and the area around the spark plug.

ENGINE ± 1NZ-FXE ENGINE
182EG05
FrontExhaust Side
Crankshaft Center
Bore Center
8 mm
Intake Side12 mm
182EG06
Taper Squish Shape47
2. Cylinder Block

A cylinder block made of aluminum alloy has been adopted to realize a significant amount of weight reduc-
tion.

A water pump swirl chamber and an inlet passage to the pump are provided in the cylinder block.

The rear portion of the cylinder block has been shaped conically to improve the coupling rigidity with the
transaxle.

Through the adoption of the offset crankshaft, the bore center has been shifted 12 mm towards the intake,
in relation to the crankshaft center. Thus, the side force when the maximum pressure is applied has been
reduced and the heat efficiency has been improved. And as a result, fuel economy has been improved.

Through the use of a thin-walled cast iron liner in the cylinder bore, a distance of 8 mm between the bores
has been realized, resulting in a compact package. This liner is thin, so that boring is not possible.

By discontinuing the use of the rear oil seal retainer and by pressing the rear oil seal into the cylinder block,
a compact package has been realized.
3. Piston

The taper squish shaped piston has been
adopted to improve combustion chamber.

Low-tension piston rings have been adopted to
reduce friction and improve fuel economy and
oil consumption performance.

By increasing the mechining precision of the
cylinder bore diameter, the outer diameter of
the piston has been made into the one type.

Important Points in the Customer Problem Analysis

What ±±±±± Vehicle model, system name

When ±±±±± Date, time, occurrence frequency

Where ±±±±± Road conditions

Under what conditions? ±±±±± Running conditions, driving conditions, weather conditions

How did it happen? ±±±±± Problem symptoms
(Sample) Engine control system check sheet.
ENGINE CONTROL SYSTEM Check Sheet
Customer's Name
Driver's Name
Data Vehicle
Brought in
License No.
Model and Model
Year
Frame No.
Engine Model
Odometer Reading
km
miles
Problem Symptoms
Engine does
not Start
Difficult to
Start
Poor Idling
Poor
Drive ability
Engine Stall
Others
Engine does not crankNo initial combustionNo complete combustion
Engine cranks slowly
Other
Incorrect first idleIdling rpm is abnormalHigh ( rpm)Low ( rpm)
Rough idling
Other
HesitationBack fireMuffler explosion (after±fire)Surging
Knocking
Other
Soon after startingAfter accelerator pedal depressed
After accelerator pedal released
During A/C operation
Shifting from N to D
Other
Data Problem
ConstantSometimes ( times per day/month)
Inspector's
Name
CUSTOMER PROBLEM ANALYSIS CHECK
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±31
2001 PRIUS (RM778U)
1. CUSTOMER PROBLEM ANALYSIS
In troubleshooting, the problem symptoms must be confirmed accurately and all preconceptions must be
cleared away in order to give an accurate judgment. To ascertain just what the problem symptoms are, it is
extremely important to ask the customer about the problem and the conditions at the time it occurred.
Important Point in the Problem Analysis:
The following 5 items are important points in the problem analysis. Past problems which are thought to be
unrelated and the repair history, etc. may also help in some cases, so as much information as possible should
be gathered and its relationship with the problem symptoms should be correctly ascertained for reference
in troubleshooting. A customer problem analysis table is provided in Diagnostics section for each system
for your use.

IN±38± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
2001 PRIUS (RM778U)
5. PROBLEM SYMPTOMS TABLE
The suspected circuits or parts for each problem symptom are shown in the table below. Use this table to
troubleshoot the problem when a ºNormalº code is displayed in the diagnostic trouble code check but the
problem is still occurring. Numbers in the table indicate the inspection order in which the circuits or parts
should be checked.
HINT:
When the problem is not detected by the diagnostic system even though the problem symptom is present,
it is considered that the problem is occurring outside the detection range of the diagnostic system, or that
the problem is occurring in a system other than the diagnostic system.
Symptom
Suspect AreaSee page
Engine does not crank (Does not start)
No initial combustion (Does not start)
No complete combustion (Does not start)1. Starter and starter relay
1. ECM power source circuit
2. Fuel pump control circuit
3. Engine control module (ECM)
1. Starter signal circuit
2. Fuel pump control circuit1. Fuel pump control circuitDI±147
DI±151
IN±29
PROBLEM SYMPTOMS TABLE
1. Compression
2. Fuel pump control circuit 1. A/C signal circuit
2. Fuel pump control circuit 1. A/C signal circuit (Compressor circuit)
2. ECM power source circuit 1. Starter signal circuit
2. Fuel pump control circuit1. Starter signal circuit
2. Fuel pump control circuit
3. Compression
idling) High engine idle speed (Poor idling) Hot engine Cold engine (Difficult to start)Engine cranks normally (Difficult to start)
AC±88 DI±144
DI±151
EM±3 DI±151

Problem Symptom
Page
Indicates the page where the flow chart for each circuit
is located.

Circuit Inspection, Inspection Order
Indicates the circuit which needs to be checked for each problem
symptom. Check in the order indicated by the numbers.

Circuit or Part Name
Indicates the circuit or part which needs to be checked.
ST±2
ST±17
DI±144
DI±151
DI±144
DI±151

IN04Q±11
IN±46
± INTRODUCTIONTERMS
46 Author: Date:
2001 PRIUS (RM778U)
TERMS
ABBREVIATIONS USED IN THIS MANUAL
AbbreviationsMeaning
ABSAnti±Lock Brake System
ACAlternating Current
ACCAccessory
ACISAcoustic Control Induction System
ACSDAutomatic Cold Start Device
A.D.D.Automatic Disconnecting Differential
A/FAir±Fuel Ratio
AHCActive Height Control Suspension
ALRAutomatic Locking Retractor
ALTAlternator
AMPAmplifier
ANTAntenna
APPROX.Approximately
A/TAutomatic Transmission (Transaxle)
AT FAutomatic Transmission Fluid
AUTOAutomatic
AUXAuxiliary
AV GAverage
AV SAdaptive Variable Suspension
BABrake Assist
BACSBoost Altitude Compensation System
BATBattery
BDCBottom Dead Center
B/LBi±Level
B/SBore±Stroke Ratio
BTDCBefore Top Dead Center
BVSVBimetallic Vacuum Switching Valve
Calif.California
CBCircuit Breaker
CCoCatalytic Converter For Oxidation
CDCompact Disc
CFCornering Force
CGCenter Of Gravity
CHChannel
COMB.Combination
CPECoupe
CPSCombustion Pressure Sensor
CPUCentral Processing Unit
CRSChild Restraint System
CTRCenter
C/VCheck Valve
CVControl Valve

A01076
EM16K±03
A01077
A01068
A01069
A01070
± ENGINE MECHANICALCYLINDER HEAD
EM±33
2001 PRIUS (RM778U)
INSPECTION
1. CLEAN TOP SURFACES OF PISTONS AND CYL-
INDER BLOCK
(a) Turn the crankshaft, and bring each piston to top dead
center (TDC). Using a gasket scraper, remove all the car-
bon from the piston surface.
(b) Using a gasket scraper, remove all the gasket material
from the cylinder block surface.
(c) Using compressed air, blow carbon and oil from the bolt
holes.
CAUTION:
Protect your eyes when using high pressure compressed
air.
2. REMOVE GASKET MATERIAL
Using a gasket scraper, remove all the gasket material from the
cylinder block contact surface.
NOTICE:
Be careful not to scratch the cylinder block contact sur-
face.
3. CLEAN COMBUSTION CHAMBERS
Using a wire brush, remove all the carbon from the combustion
chambers.
NOTICE:
Be careful not to scratch the cylinder block contact sur-
face.
4. CLEAN CYLINDER HEAD
Using a soft brush and solvent, thoroughly clean the cylinder
head.

A01479
A01075
Cylinder Block Side
Intake Manifold Side
Exhaust Manifold Side
A01071
EM0580
EM±34
± ENGINE MECHANICALCYLINDER HEAD
2001 PRIUS (RM778U)
5. CLEAN VALVE GUIDE BUSHINGS
Using a valve guide bushing brush and solvent, clean all the
guide bushings.
6. INSPECT FOR FLATNESS
Using a precision straight edge and feeler gauge, measure the
surface contacting the cylinder block and the manifolds for war-
page.
Maximum warpage:
Cylinder block side0.05 mm (0.0020 in.)
Intake Manifold side0.10 mm (0.0394 in.)
Exhaust manifold side0.10 mm (0.0394 in.)
If warpage is greater than maximum, replace the cylinder head.
7. INSPECT FOR CRACKS
Using a dye penetrant, check the combustion chamber, intake
ports, exhaust ports and cylinder block surface for cracks.
If cracked, replace the cylinder head.
8. CLEAN VALVES
(a) Using a gasket scraper, chip off any carbon from the valve
head.
(b) Using a wire brush, thoroughly clean the valve.