How to wire a 4g63 engine

From HotrodWiki

<< Back to 4G63 Swap Info

4G63 wiring for an engine swap

  • 1990 4G63 engine swap wiring schematic diagram (seen in image)
1990 4g63 wiring schematic diagram / schematic for a 1990 DSM 4g63 engine.
  • 1991-94 4G63 engine swap wiring schematic diagram (seen in image)
1991-94 4g63 wiring schematic diagram / schematic for a 1991-94 DSM 4g63 engine.

4G63 MPI Relay (Connector C-63)

  • The MPI relay distributes power to the 4G63 engine. If you wire it wrong, you will have problems like your fuel pump not turning on, ECU not powering up properly, etc. Learn how to wire a 4G63 MPI Relay here.
  • Unplug the MPI connector from the MPI relay and look straight into the pins at the end of the wiring connector. Wires away from you. Make sure the clip that locks the connector into the MPI relay is facing up.

The order of pins are:

123 45
678 910
  • Pin 1 - Empty.
  • Pin 2 - Black w/ green stripe - Goes to the fuel pump and a test connector. The test connector is used to jump the fuel pump if the MPI relay doesn't turn it on. Many people rewire their fuel pump with 8 gauge wire to make sure it has a strong battery-fed power feed. If doing this, you can use this factory black w/ green stripe on pin 85 of a Bosch relay. Then pin 86 on the Bosch relay would be a ground. Pin 30 on the Bosch relay would be the 8 gauge power feed from the battery (fused of course). Pin 87 on the Bosch relay would be the power wire going to the fuel pump itself. Learn how to wire a Bosch Relay here.
  • Pin 3 - Black w/ white stripe - Ignition power and pin 110 at the ECU. It also powers the Ignition Coil and Power Transistor.
  • Pin 4 - Red wire - Goes to Pin 107 and 102 on the ECU. It also jumps over to Pin 5 on the MPI relay, and sends power to the:
Airflow Sensor
Crankshaft Position(Angle) Sensor (CAS)
Wastegate Solenoid
Idle Speed Control Actuator (ISC)
O2 Sensor
Injector Resistor
Purge Control Solenoid
Fuel Pressure Solenoid
EGR Solenoid (California Models Only)
  • Pin 5 - See Pin 4 above
  • Pin 6 - Black wire - Goes to ground.
  • Pin 7 - White w/ a red stripe - pin 56 at the ECU
  • Pin 8 - Black w/ blue stripe - Goes to Pin 63 and 66 at the ECU.
  • Pin 9 - Black with a Yellow Stripe - Goes to Pin 108 at the ECU and the starter relay. This should ONLY have power when the engine is cranking from the starter. The moment you let go of the key when the engine starts, this wire should no longer have power.
  • Pin 10 - Black w/ red stripe - Goes to fusible link #1 in the main fuse box of the DSM (Eclipse / Talon / Laser). The fusible link #1 is a 20A fed directly off the battery.

4G63 Fuel Injector Wiring

  • #1 cylinder (Connectors B-10) (front cylinder, closest to water pump)
Pin 1 - Black w/ yellow stripe
Pin 2 - Yellow w/ blue stripe
  • #2 cylinder (Connectors B-09)
Pin 1 - Black w/ blue stripe
Pin 2 - Yellow w/ black stripe
  • #3 cylinder (Connectors B-06)
Pin 1 - Black w/ white stripe
Pin 2 - Light green
  • #4 cylinder (Connectors B-01) (rear cylinder, closest to transmission)
Pin 1 - Black w/ red stripe
Pin 2 - Light green w/ white stripe

4G63 Fuel Injector Resistor wires: (Connector A-58)

Note: This connector is the same 6 pin connector as the ISC connector. Don't mix them up accidentally when installing your wiring harness into your vehicle.
  • Pin 1 - Black w/ yellow stripe
  • Pin 2 - Empty
  • Pin 3 - Red
  • Pin 4 - Black w/ blue stripe
  • Pin 5 - Black w/ white stripe
  • Pin 6 - Black w/ red stripe

4G63 MAF (Mass Air Flow) wires: (Connector A-36)

The non-turbo vs. turbo MAF sensor connectors are different. You can see the difference of 4G63 N/T vs. Turbo MAF sensor connectors here.
  • Pin 1 - Green w/ white - pin 6 at ECU
  • Pin 2 - Green w/ blue - pin 10 at ECU
  • Pin 3 - Red - Power fed by pin 102 & 107 at ECU ((Shared by O2 sensor, EGR & Purge solenoids, Injector resistors, ISC, MPI relay, CAS))
  • Pin 4 - Green w/ red - Power fed by Pin 23 at ECU (shared with TPS)
  • Pin 5 - Empty.
  • Pin 6 - Green w/ black - Ground for Sensor Pin 24 & 17 at ECU (Shared with ECT, TPS, EGR Temp)
  • Pin 7 - Green w/ yellow - pin 16 at ECU
  • Pin 8 - Green w/ orange - pin 8 at ECU

4G63 ISC (Idle Speed Control) Motor wiring: (Connector B-04)

Note: This connector is the same 6 pin connector as the injector Resistor connector. Don't mix them up accidentally when installing your wiring harness into your vehicle.
  • Pin 1 - Blue - Goes to pin 58 at ECU
  • Pin 2 - Red
  • Pin 3 - Yellow - Goes to pin 59 at ECU
  • Pin 4 - Black - Goes to pin 68 at ECU
  • Pin 5 - Red
  • Pin 6 - White -Goes to pin 67 at ECU

4G63 CAS (Camshaft Angle Sensor) Wiring (Blue Connector A-32)

  • Pin 1 - White - Goes to pin 22 at ECU.
  • Pin 2 - Black - Goes to pin 21 at ECU.
  • Pin 3 - Red - Power fed by Pin 102 & 107 at ECU (Shared by O2 sensor, EGR & Purge solenoids, Injector resistors, ISC, MPI relay, MAF)
  • Pin 4 - Black - Goes to ground (To engine).

4G63 TPS (Throttle Position Sensor) Wiring (Black Connector B-02)

The 1990 TPS is different than the 1991-94 style. The 1991-94 TPS has a separate idle switch (Connector B-05). 1990 has the idle switch built into it.
  • Pin 1 - Green w/ red - Goes to pin 23 at ECU (also shared with MAF).
  • Pin 2 - Green w/ white - Goes to pin 19 at ECU.
  • Pin 3 - Empty
  • Pin 4 - Green w/ black - Ground for sensor pin 24 & 17 at ECU (Shared with MAF, ECT, EGR Temp).

4G63 Knock Sensor Wiring (Connector B-07)

  • Pin 1 - White - Goes to pin 9 at ECU.
  • Pin 2 - Black w/ white - Goes to ground.

4G63 Thermostat Housing (Upper) 2 Pin Fan Switch / Temperature Sensor (Connector B-31)

This is the coolant temperature switch that turns on the fan(s).
  • Pin 1 - Green w/ yellow stripe - Goes to an A/C switch.
  • Pin 2 - Black w/ green stripe - Goes to pin 7 at ECU.

4G63 Thermostat Housing (Middle) 2 Pin Temperature Sensor for the ECU (Connector B-30)

This is the coolant temperature sensor for the ECU. It tells the computer if your engine is hot or cold. It also gives the temperature to your datalogging device (through the ECU ofcourse).
  • Pin 1 - Green w/ black stripe - Sensor Ground - Goes to Pin 24 at ECU.
  • Pin 2 - Yellow w/ green stripe - Goes to pin 20 at ECU.

4G63 Thermostat Housing (Lower) 1 Pin Temperature Gauge Sensor (Connector B-29)

This is for the factory temperature gauge. A simple 1 wire connector.
  • Pin 1 - Yellow w/ green stripe - Goes to factory temperature gauge.

4G63 Ignition Coil Wiring (Connector B-14)

1990 vs. 1991-94 Ignition coils have different connectors. The 1990 has a square connector, and the 1991-94 has a triangle connector. See both 4G63 ignition coil connectors here. 1990 on the left. 1991-94 on the right.
  • Pin 1 - Yellow w/ black stripe - Goes to Pin 1 of the power transistor.
  • Pin 2 - Yellow w/ green stripe - Goes to Pin 8 of the power transistor.
  • Pin 3 - Black w/ white stripe - Receives 12v power from ignition switch being in the "Run" position.

4G63 Ignition Power Transistor Wiring (Connector B-15)

The 1990 vs. 1991-94 Ignition Power Transistors are different shapes. This is a comparison of the 1990 vs. 1991-94 4g63 Power Transistor here. 1990 on the left. 1991-94 on the right.
  • Pin 1 - Yellow w/ black stripe - Goes to Pin 1 of the ignition coil.
  • Pin 2 - Yellow w/ red stripe - Goes to Pin 55 of the ECU.
  • Pin 3 - Black - Goes to ground.
  • Pin 4 - White - Goes to pin 109 at the ECU.
  • Pin 5 - Empty.
  • Pin 6 - Black w/ white stripe - Goes to Pin 3 at the ignition coil which is fed 12v power from the ignition switch.
  • Pin 7 - Yellow - Goes to pin 54 at the ECU.
  • Pin 8 - Yellow w/ green stripe - Goes to pin 2 of the ignition coil.

4G63 Oxygen Sensor (Connector B-26)

  • Pin 1 - White - Goes to pin 9 at the ECU
  • Pin 2 - Black - Goes to ground. Grounds the shields for the O2 Sensor wiresand the knock sensor wires.
  • Pin 3 - Red - Goes to pin 102 at the ECU (Shared power wire for multiple sensors)
  • Pin 4 - Black - Goes to ground

4G63 Wastegate Solenoid (Connector A-51)

  • Orange - Goes to pin 105 at the ECU
  • Red - Goes to pin 107 at eco (Shared power wire for multiple sensors)

4G63 Starter Motor Circuit

  • The 4G63 starter is wired like every starter in every car. I always recommend using the starter wiring from whichever car you'll be swapping a 4G63 into. There is a main power feed from the positive battery terminal (fused), and then a smaller wire coming from the ignition switch which tells the starter when to turn. The MPI relay Pin 9 (black w/ yellow stripe) wire does need to be tapped into the small wire going to the starter. The MPI relay wire receives power from the small starter wire when the engine is attempting to start. As soon as you let go of the key so the starter isn't turning, the MPI's Pin 9 wire should go to 0 volts.

OBD (On Board Diagnostic) Connector

  • Pin 1 - Yellow - pin 1 at the ECU
  • Pin 10 - White - pin 2 at the ECU
  • Pin 11 - Yellow w/ white stripe -
  • Pin 12 - Black - Goes to ground