Tag Archive for lexus d4-s

Disecting the DI system

just some rough notes in how we might control the DI EDU’s



update on DI fueling and AA80E 8 speed to be used in the Supra

Just a quick update. We have decided to run the AA80E box, along with the IS-F Differential. We will be controlling the box via custom contoller with paddle shift changes.

The DI fueling is still a major headache though i have more information on it now including schematics, wiring, control etc etc

This is the most important part of this swap.
Max Orido decided to by pass DI, and unfortunately it caused major engine failure.
The DI injectors heated up as they had no fuel flowing though them (an inbuilt mechanism for cooling) and caused Det melting one piston, and melting an injector tip in another cylinder.



IS-F engine + TCM Wiring Diagram and ECU Pinouts

in all its Glory! in PDF formatt mind you,

IS-F ECM Pinout

IS-F Wiring Diagram

IS-F Wiring B (plugs)


Some DI insight

well still awaiting my IS-F tech doc, but heres the basic control system employed by toyota and lexus on thier DI system..

VVT-IE – some new info on its operation

Trying to get info on the VVT-IE system has been a struggle. This is the latest info that I have been able to find.



1. System structure

Engine control system
VVT-iE system diagram camshaft control motor assembly

Angle sensor

Engine ECU (ECM)

EDU motor

Crankshaft position sensor

Camshaft position sensor

VVT sensor

VVT-IE system overview


2. Command control

VVT-iE EDU control the motor, and feedback the state of the motor to the engine ECU (ECM)
Camshaft control motor

Motor speed and direction of rotation command signal

Angle sensor
EMR1 motor actual speed of the VTS

Engine ECU (ECM)

EMF1 actual motor direction of rotation of VTD

Motor (12V)


Fault information



3. EDM1 – VTM is the diagnostics line between EDU and ECU. Uses a PWM control to relate to ECU and problems.

VVT-iE from the ECU error conditions the duty cycle

Camshaft control motor

VTP and EDT1 open to 100% the Speed ​​Motor and the Rotation 80% normal EDT1 of the Direction the Command the Signal the VTP EDU overheating, 60% motor voltage failure

Engine ECU (ECM)


Angle sensor fault Actual, Motor Speed

40% of VTS 20% of VTD

Rotation, the Angle Sensor EDU Motor (12V)

Motor overcurrent protection mode Actual Motor Rotation EMF1 Direction EMD1 5V


Fault information

VVT-IE diagnostics line


So now at last, we are getting a better understanding of the components




Engine test fit – 2urgse into a Supra…yes it does

Well doing a lot of research before this project began has been paying off. According to the Lexus collision repair manual we had aound 1″ on each bank to play with when sized with the jza80 bay dimensions. So today we placed the lump into the bay..and well..we have a good 1″ of clearance on each bank. As we have also lost the AC pump, this leaves room for future components i.e. PS pump or Superchager. Yes boost is good on a Hi comp engine thanks to Direct injection technology..if we can find a way to contol that off course

The Sump fits exactly were the 2jz did, but we will be taking around 1.5″ from the rear member to bring the engine back another bit. The Engine mount backets also place the mounts quite close to the original 2jz point on on the subframe, which should mean custom mounts to tie things up.

Transmission tunnel and rear bulk head clearance can be summed up with a great saying here “you would get a bus through there bai!!!”

2urgse in a mkiv supra2urgse in a mkiv supraalways have a big hammer at the ready ;)

2urgse in a mkiv supra

2urgse in a mkiv supra

2urgse in a mkiv supra

2urgse in a mkiv supra and the bonnet closes

and even the bonnet closes


So next step will be sorting the rear crossmember and mounting

D4-S fueling system and a 11.8:1 compression

What we want to tame :-


The 2UR-GSE engine has Lexus D-4S stoichiometri c, four-stroke, direct-injection technology, which combines the strengths of high-pressure direct petrol injection and low-pressure port injection.

The system mixes and matches fuel delivery from the two sets of injectors to provide the ideal fuel/air mixture for all engine load conditions.

It helps optimise performance and fuel economy, and minimise emissions.

D-4 direct injection, as used in Lexus GS 300 and IS 250 engines, boosts torque across the engine revolution range.

The D-4S system used in GS 450h, GS 460, LS 460, LS 600hL and IS F further boosts torque across the range.

The two injection systems have their own fuel supply systems.

When the engine is running under medium-to-high load at lower engine revolutions, both systems are used.

This creates a homogeneous air/fuel mixture to stabilise combustion, improve fuel efficiency and reduce emissions.

In high-load situations the engine uses the direct injection system only, taking advantage of the cooling effect of injecting fuel directly into the combustion chamber and hence improving the efficiency of each charge.

The precise injection control also allows for a high compression ratio by reducing the chance of pre-ignition or detonation.

The IS F D-4S dual injection engine has a compression ratio of 11.8:1, compared with 11.5:1 in the direct-injection GS 300, for better performance.

When the engine is cold, the injection system uses both sets of injectors to ensure quick warm-up of the catalyst and hence optimum purification of exhaust emissions.

Lexus has reduced the size of the port injector body, to provide optimum cross-sectional area for the inlet port.


Direct injection hardware:

The direct injection equipment in IS F’s new engine includes compact, high-pressure double slit-nozzle injectors to maximise fuel atomisation.

The injector atomises fuel into a fine mist and expands it to form a large, fan-shaped pattern in the combustion chamber.

This occurs as the down stroke of the piston draws in a large volume of air. The cooling effect of the fuel increases the intake air volume and improves charging efficiency.

Importantly, the intake air forms a vertical swirl current (tumble current) to promote improved air/fuel mixing and hence improve performance and emissions.

The injector has a special coating on its nozzle to resist deposits.

The area where the injector body meets the cylinder head has an insulator, and the injector shaft has two Teflon-coated seals – to resist cylinder pressure, improve sealing performance and reduce vibration.