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Audi 4/5 cylinders

Single-piece intake manifold

5-cyl engines: HX,HY,JT,KE,KF,KK,KL,KU,KV,KX,KZ,PR,PX,WB,WC,WG,WK,WU

4-cyl engines: AAD, ACE, 9A, PL

This manual is based on the 5-cylinder engine. The 4-cylinder engine is fundamentally similar, with minor differences in layout and one fewer cylinder.

Video of installation on VW 16V engine

Removing mechanical injector

Detach the mechanical injectors along with the distributor.

The airflow sensor plate is no longer required. Remove it and secure the moving component beneath with a plastic strap.

Bend the injector ventilation pipe to allow the installation of the fuel rail.

Injector sleeves

Attention

In rare instances, sleeves are entirely constructed from plastic. It is required to replace them with metal ones, as illustrated in the images below.

Carefully unscrew the injector sleeves, ensuring caution as the sleeves consist of three parts that may fall into the engine.

The plastic component can be removed using the thread tap.

We only need this part. Reinstall it using engine sealant.

Install additional O-rings on the injectors. Lubricate the O-rings, then insert the injectors into the sleeves until they click into place.

The O-ring on the injector tip must be properly seated.

Fuel rail

Lubricate the O-rings with water and position the fuel rail appropriately.

Bend the metal brackets of the rail and drill a hole in each bracket to insert the screw that will secure it to the intake manifold.

Ensure the injectors are fully inserted without any misalignment.

Fuel lines and filter

The fuel lines are now ready for installation.

The metal cylinder with three fittings serves as both a fuel filter and a pressure regulator, necessitating the removal of the old original unit.

  • Connect the feeding line from the fuel pump to the "IN" fitting.
  • Attach the return line, which goes back to the tank, directly to the unnamed central fitting.
  • Connect the main line leading to the fuel rail to the "OUT" fitting.

Utilize the three black junctions included in the kit to connect the rubber line to the filter/pressure regulator, ensuring they are securely mounted.

Once the fuel lines are installed, cycle the ignition on and off 5-6 times without engaging the starter to build pressure in the fuel lines.

Thoroughly inspect for any potential leaks.

The fitting features a cone-shaped seal that tightens under fuel pressure. If you notice a leak, try gently moving the fitting back and forth. If it continues to leak, remove it and apply a small amount of oil to the sealing parts.

Idle valve

Clean the valve internals using carburetor cleaner and lubricate them with oil. Avoid using WD-40, as it is not a good lubricant. Bicycle chain lubricant is well suitable for this purpose.

MAP sensor

The precise placement of the MAP sensor is crucial for optimal engine performance. Please position the MAP sensor exactly as shown on the photo

Drill a 13mm hole for the sensor and an 8mm hole for the securing bolt. Apply grease to the drill tip to capture debris. It is recommended to clean the intake manifold thoroughly after drilling to ensure no metal debris remains.

Apply a sealant to fill the hole, ensuring an adequate amount of sealing paste is used due to the rough surface of the intake manifold.

Secure sensor with included screw. Apply sealant to the thread, to prevent air leaks and unscrewing.

Never install the sensor with the wires facing upwards to prevent water from running along the cable, which could lead to connector flooding and subsequent oxidation.

Secure the sensor using the screw. Apply sealant to the threads to prevent air leaks and ensure the sensor remains securely fastened.

Warning

Installing a MAP sensor in place of a cold start injector is strictly prohibited.

ECU and wiring

Warning

Disconnect the battery when servicing the electrical system. Reconnect the battery only when the engine needs to be started.

The ECU is designed to be dust and splash-resistant but is not suitable for continuous exposure to water or pressurized water. It is recommended to install it in a dry and secure location. Ensure that the ECU is not installed with the cable facing upwards, as this may allow water and moisture to enter the unit.

Warning

Wire colors may change without prior notice. If wires have text labels, use these labels to identify the purpose of each wire.

This is the wiring configuration.

The wiring harness for 4-cylinder and 5-cylinder engines is identical. For a 4-cylinder engine, leave the connector for injector #5 unconnected.

This photo provides an overview of the installation, including key mounting points. The ECU is installed in the position formerly occupied by the mechanical injection distributor. Begin the wiring process by locating the ECU and connecting the injectors. Once these components are connected, the remaining wiring will naturally fall into place.

AFS emulator

Attention

For the RT engine, the AFS emulator is unnecessary. Please proceed to the next chapter.

Plastic box #1 must be removed from the distributor while remaining connected; otherwise, the stock ECU will display an error.

Remove the middle wire from connector #2 and connect it to the EMUL wire.

It should be insulated using shrink tubing or electrical tape.

Measure the resistance between pins 1 and 3 of connector #2. It should be between 3 and 5 kOhms. If the resistance is outside this range, inspect the wires near the connector for signs of oxidation or damage.

Connector #2 should be reconnected to its original position

Hall sensor

Locate the hall sensor connector on the ignition distributor.

Connect the DH wire in parallel to the central wire of the Hall sensor connector.

Lambda sensor

Connect the LAMBDA wire to the signal wire of the lambda probe (refer to the attached photo).

Attention

Ensure the lambda is disconnected from the stock ECU to prevent any interference.

If your vehicle lacks a lambda sensor or if the existing sensor is malfunctioning, it is recommended to install a universal Bosch sensor, either model 0258986507 or 0258006537.

The original lambda probe features three wires: ECU signal, ECU ground, and heater +12V. It does not include a heater ground wire, as the exhaust pipe serves as the ground.

The new lambda probe is designed with two separate heater wires, and the heater is isolated from the sensor housing, providing a more robust design.

Connection diagram:

  • White wires: Connect one to the lambda heating connector or the fuel pump supply, and the other to the car chassis.
  • Black: Connects to the LAMBDA wire of the ECU
  • Gray: Connects to the ground point of the ECU

Throttle position switches

Disconnect the stock connector and measure the resistance of the idle switch. The resistance should be between 0 and 5 Ohms. If it exceeds this range, the switch is likely worn out and should be replaced.

Connect the IDLE SW in parallel with the idle switch wire (position #1 at the connector).

Connect the FULL SW in parallel with the full throttle switch wire (position #3 at the connector).

Coolant temperature sensor

The CLT wire should be connected in parallel to pin #2 (black-red) of the coolant temperature sensor. If the wire colors differ, use a multimeter to identify the correct pin. The correct pin will show a 5V reading when the connector is disconnected from the sensor.

Idle valve

Disconnect the old idle valve connector and connect the new one labeled "IDLE."

Attention

Only a 2-wire idle valve is supported. An external circuit is required for a 3-wire valve. For further details, please refer to the Additional Information section at the end of the document.

Power

Connect the power wires to the battery and securely mount the main relay in close proximity to the battery.

Attach the COIL +12 wire to the +12V terminal of the ignition coil. This wire is responsible for activating the main relay.

LPG

Connect the EXT wire to the gas supply valve and activate the LPG mode by EXT input in the settings. The ECU will then adjust to operate on gas fuel.

For carburetted LPG systems, it is unnecessary to disconnect the power from the gasoline injectors. Simply select the Turn off injection option, and the fuel supply will be interrupted by the signal from the EXT. Connect the EXT wire to the gas supply valve and activate the LPG mode by EXT input in the settings. The ECU will then adjust to operate on gas fuel.

Air conditioner

Connect the AC (or EXT) wire to the air conditioner clutch wire. This connection is essential for maintaining the idle RPM when the air conditioner is engaged.

K-Line

To connect the K-Line cable, you will need to prepare three wires: Typically, the Bluetooth interface is used to connect to the ECU. However, in rare instances where the Bluetooth connection proves unreliable, the K-Line can be utilized as an alternative.

To connect the K-Line cable, you need 3 wires:

  • 12V
  • Ground
  • K-line

Pinout of the K-Line cable:

Pinout of the car OBD2 connector

Other wires

This manual does not mention certain additional wires, which are reserved for future use. Please ensure that any unused wires are isolated and concealed within the harness.

Distributor

Distributor preparation for phased injection

This operation is optional. If performed, it will result in sequential phased injection, which is essential for CNG/LPG conversion. For petrol engines, batch injection is sufficient for optimal performance. However, phased injection can enhance fuel economy slightly during cruising.

This manual is applicable regardless of the distributor model or rotation direction. If your distributor differs from the one shown in the photo, simply adhere to the instructions in the manual to achieve the proper result.

Place a mark on the distributor case

Take off the distributor cap. Turn the crankshaft to align the rotor with the mark.

Position the engine at Top Dead Center (TDC). The rotor should remain aligned with the mark.

Remove the rotor and the plastic cap. Mark the window edge at the center of the hall sensor. The marked window edge should then be widened.

Please widen the window edge by precisely 1.1mm. Ensure maximum precision in this adjustment. If the PHASE indicator in the program becomes unstable, increase the window width by an additional 0.1mm. Conversely, if the window becomes too wide, idling may become unstable.

Additional info

MAP sensor pinout

Invent Jetronic ECU pinout
8 7 6 5 4 3 2 1
A IDLE INJ1 INJ2 INJ3 INJ4 INJ5 INJ6 X1**
B +12V CLT TPS AN KLINE EMUL IDLE SW FULL SW
C GND 5V OUT IAT MAP LAMBDA EXT DH AC*

() - available in version 2.3 (*) - available in version 2.5

3-wire IAC valve

This valve contains two windings: one for opening and another for closing.

An external circuit is necessary to connect this valve. A MOSFET capable of handling over 5A of current and more than 55V of voltage is used (for example IRFZ44)

The dotted line represents the IAC case

Abbreviations

  • MAP - absolute pressure sensor
  • TPS - throttle position sensor
  • IAT - sensor air temperature
  • CLT - coolant temperature sensor
  • DH - Hall sensor
  • AFS - airflow sensor