1UZ-FE Engine

1UZ-FE Engine

Information on the Toyota 1UZ-FE Engine








Haltech ECU Options

All Haltech ECU models can run the engine.   Elite 1000 and higher is required to control the factory stepper motor idle valve.  Elite 950, 2000, and 2500 are required for sequential injection upgrade.





General Information

Cylinders
8
Displacement

1UZ 3969cc 242ci

2UZ 4663cc 284ci

3UZ 4292cc 262ci

Firing Order
1,8,4,3,6,5,7,2
Cylinder Orientation
1,3,5,7 on LHS (from drivers seat





Model Variants

There are a number of variants of the 1UZ engine.

1UZ-FE (1989-1995)

4L V8, alloy block, 10.0:1 comp, 12x crank trigger, 1x cam trigger

1UZ-FE (1995-1997)

10.4:1 comp, 12x crank trigger, 1x cam trigger

1UZ-FE VVTI (1998-on)

10.5:1 comp, Variable Cam Timing on Inlet Cams (continuous type), 36-2 crank trigger, 3x cam trigger

2UZ-FE (1998-2005)

4.7L V8, iron block, 36-2 crank trigger, 3x cam trigger

2UZ-FE VVTi (2004-on)

Variable Cam Timing on Inlet Cams (continuous type), electronic throttle, 36-2 crank trigger, 3x cam trigger

3UZ-FE VVTi

4.3L V8, Alloy block, Variable Cam Timing on Inlet Cams (continuous type), 36-2 crank trigger, 3x cam trigger


Common Models

Engine Type
Common Vehicles
1UZ
Soarer SC400
Aristo GS400
Celsior LS400
Crown
2UZ
Land Cruiser (MY98-05)
4Runner (MY99-04)
Tundra (MY99-04)
GX470 (MY02-04)
LX470 (MY98-05)
Sequoia (MY00-04)
2UZ VVTi
Land Cruiser (MY05-11)
4Runner (MY05-09)
Tundra (MY04-09)
GX470 (MY04-09)
LX470 (MY05-07)
Sequoia (MY04-09)
3UZLS430
GS430
Soarer SC430
Crown Majesta
Hongqi HQ430






Sensor Information

Crank/Cam Sensor

This engines uses a Crank Position Sensor and 2x Cam Position Sensors (1x per bank).


Early 1UZ

These models use a 12x tooth crank trigger and a 1x tooth cam trigger.  Configuration is shown below.


1UZ VVTi and all 2UZ and 3UZ

These models use a 36-2 tooth crank trigger and a 3x tooth cam trigger. Configuration is shown below.



12x on the Left and 36-2 on the Right





Crank Sensor

A Reluctor crank position sensor is used.









Cam Sensor

Reluctor cam sensors are used.  1UZ motors have these located under the cam drive pulley on each bank.  The cam pulley has a backing plate with a single tooth.





VVTi models

These use the same sensor arrangement with a 3-tooth backing plate on the cam pulley.





Distributor

The 1UZ-FE has twin distributors. These do not contain any advance mechanism and are simply there to distribute spark to each cylinder.















Ignition Coils and Igniters

Early 1UZ models have 2x igniters and 2x coils.  The igniters have the same wiring.
All models use Constant Charge with a Falling output edge.








Direct Fire Coil Models

All models with Direct Fire ignition feature coils with internal igniter modules.






Dwell Time

Distributor Models



Direct Fire Models







DBW Throttle System

Models that have the ETCS-i throttle system are not supported by Haltech.
Models that use a normal cable throttle, or have full DBW (no throttle cable) are supported.
All variants use a single throttle body.



DBW Throttle Wiring

Position Sensors
Pin
Description
Haltech Connection
1
5V+
5V+
2
TPS2
AVI3
4
TPS1
AVI2
5
Signal Ground
Signal Ground

Drive Motor
Pin
Haltech Connection
3
DBW1
6
DBW2



DBW Accelerator Pedal Position Sensors Connection



Pin
Description
Haltech Connection
1
Signal Ground
Signal Ground
2
APP2
AVI5
3
Signal Ground
Signal Ground
4
5V+
5V+
5
APP1
AVI4
6
5V+
5V+








Throttle Position Sensor

Early 1UZ models use a cable throttle with a conventional throttle position sensor.
This engine uses a cable operated throttle body with a position sensor.

OEM Wiring
Haltech Wiring
A
5V+
B
Signal (Spare AVI)
C
Closed Throttle Switch - NOT USED
D
Signal Ground








MAP Sensor

These engines do not come with a MAP sensor.
Use the internal MAP sensor that comes with your ECU.  For higher boost levels an external MAP sensor should be used instead, connected to a spare AVI.









Variable Cams

Engines with VVTi have Toyotas Gen 3 continuously variable cam control. The ECU uses a 3x tooth cam sensor on each inlet cam to know the position of the camshafts relative to the crank position. A duty signal is sent to each cam control solenoid. The solenoid regulates oil pressure being fed into the cam control mechanism to advance or retard the cams to their target position using closed-loop.  They cannot be sent to a specific position using open loop.







Idle Valve

The cable throttle 1UZ engine uses a Stepper Motor idle valve controlled via the Stepper Outputs.  It will not work on Elite 550/750/950 ECU models.


Pin
Haltech Connection
AStepper 4
B12V+ Ign Switch or No Connection
CStepper 3
DStepper 1
E12V+ Ign Switch or No Connection
FStepper 2
Drive Type: Low Side if 12V+ is connected. Both if 12V+ is not connected
Steps:240     Speed:75









Coolant Temperature

Located near the RHS Distributor.


Wiring is not polarity sensitive
Pin
Haltech Connection
1
Any Spare AVI*
2
Signal Ground
An AVI with a selectable Pullup should be used.  If not and external 1k pullup to 5V should be connected.

Calibration: Use "Temperature - xxxxxxx.cal"
Created for Haltech ECUs using a 1k pullup to 5V








Air Temp

An air temperature sensor is incorporated in the MAF Sensor.  If the MAF is deleted then an external Air Temperature Sensor needs to be installed in the intake, preferably in the plenum near to where the MAP sensor connects.

Haltech 1/8" NPT Air Temp Sensor


Wiring is not polarity sensitive.

Calibration: Use "Temperature - GM Air Sensor.cal"
Created for Haltech ECUs using a 1k pullup to 5V








Knock Sensor

The 1UZ has 2x resonant style single-wire knock sensors located in the intake valley near the starter motor.  Although they can be used they are not as reliable as newer donut style resonant sensors.



Recommended Knock Sensor.  Haltech HT-011100










MAF Sensor

Although most users of Haltech ECUs will be deleting the MAF, it is possible to use a MAF if you prefer. It also incorporates an Air Temperature Sensor, so if the MAF Sensor is removed a new Air Temperature Sensor must be installed in the intake.

1UZ Early

The early 1UZ use a Frequency based MAF Sensor.  It is not a normal 0-5V signal.





Pin
OEM Wire Colour
Connection
1
Brown
Signal Ground
2
Yellow/Black
Air Temperature (AVI)
3
Yellow/Green
MAF Signal (SPI or DPI)
4
Blue/Red
5V+
5
Brown
Signal Ground


2UZ




Pin
Description
Haltech Connection
1
B+ (Power)
12V+
2
E2G (MAF Ground)
Signal Ground
3
VG (MAF Signal)
SPI or DPI
4
THA (Air Temp Signal)
AVI
5
E2 (Air Temp Ground)
Signal Ground










O2 Sensors

1UZ engines have 4x Narrowband 4-wire O2 sensors.  Narrowband sensors are not useful for tuning and are used primarily for catalytic converter efficiency.



O2 Sensor Wire Colours
Haltech Connection
Black (Signal)
AVI 1 or AVI 6
Grey
Signal Ground (Black/White)
White
12V+ Switched
White
Chassis Ground (not Signal Ground) or Spare Output
It is possible for the ECU to supply a duty signal to the Heater Ground, with many OEM ECUs doing this.  Haltech ECUs can also perform this task and a spare Injector or Stepper Output should be used.
O2 Sensors can use various wattage heater elements, with 12W and 18W being common.  For 18W units it is advised to not supply more than ~50% duty to prevent excessive current being applied to the ECU output.

For post-cat sensors it is advised to not enable the heater ground control until the engine is at full operating temperature. This is to prevent moisture in the exhaust from a cold started engine from damaging the heater element.  Many OEM strategies involve not enabling the heater until the engine have been driven above a set speed for a set amount of time.


For correct operation a Haltech WB2 kit is highly recommended for this application, with the provided 4.9 sensors replacing the pre-cat sensors.  Swapping the sensors is accessed only from below the vehicle.  Sensors use a 22mm socket or spanner to remove and replace.












Vehicle Speed Sensor

This engine uses a Reluctor Vehicle Speed sensor.

Reluctor Speed Sensor Wiring
OEM Wiring
Description
Signal +
Any Spare SPI
Signal -
Signal Ground










Injector Data

Early 1UZ engines have only 4x injector outputs from the OEM ECU, run as semi sequential. They are joined in the OEM wiring as 1+7, 2+8, 3+5, 4+6
1UZ VVTi and all 2UZ and 3UZ engines have sequential injection

Flow

The injector flow rate is measured with the injectors held wide open at 100% duty.  For fuel systems with a fixed regulator pressure (often returnless systems) that is not referenced to manifold pressure the flow needs to be mapped over Manifold Pressure for accurate tuning.

Early 1UZ-FE have 240cc/min injectors.



Dead Time

When an injector is commanded to open for a certain amount of time, the dead time is the amount of time the injector is not actually open during this period.  It covers the time to energise the solenoid and begin to open and the time to close as well.  There are also transient periods during which the injector is opening and closing where fuel flow is not at full capacity so this lost peak flow period is also taken into account.  















OEM ECU Information

There are a number of different ECU connectors found on the 1UZ, 2UZ and 3UZ ECUs.

1UZ-FE ECU




LS400 (MY98-00)
   



Soarer UZZ30
   



2UZ-FE ECU

   


3UZ-FE ECU

   





ECU Pinout

TBA
   



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