EGI Wiring

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Wiring for the Datsun A14/A15 EFI (EGI) system.

Datsun Factory Fuel Injection EGI main article EGI Wiring EGI Photo Index A14E Service Manual Introduction of GX-E 200SX EFI

Overview

Wiring here is based on Datsun S110 (Silvia/Gazelle/240RS), specifically the 1981 USA "200SX" version.

The simplified "4-wire" setup, which assumes you are using a factory wiring harness cut out of a donor car, is:

• IGN
• START
• GROUND/EARTH
• FUEL PUMP

Engine Harness

Engine harness

• Injectors
• Air Regulator (air bypass system -- for idle speed)
• EGR/VVT vacuum-cut switch (can be disconnected)
• Throttle Sensor (Throttle position sensor)

ECU

• 22612-N7801 to 0681 (no O2)
• 22612-N8500 from 0781 (O2 sensor)
• Wires to passenger compartment
• EFI relay
• INPUTS
  • coil negative (tach sense)
  • air flow meter
  • air temp sensor (in flow meter)
  • throttle valve sensor
  • START wire for ignition switch (to indicate when to do cold-start enrichment)
  • water temp sensor (on underside of intake manifold)
  • O2 sensor (not used on early B310)
• OUTPUTS
  • Injector output

Fuel Pump Wiring

• 2 wires to pump
  • B - earth/ground
  • LgR - (Light Green with Red stripe) pump power
• 3 relays (FUEL PUMP RELAY 1, FUEL PUMP RELAY 2, FUEL PUMP RELAY 3)
  • The extra relays are for safety. Relay takes inputs from Alternator, Oil pressure switch and ECU. Pump will shut off if engine dies because Oil and Charge will go out. This is important for safety in a crash.

Dropping Resistor

Fuel injector dropping resistor: 2.35 ohms resistance. Two blue (L) wires.

EFI Relay

Needed: One relay, one Fusible Link, 20 gauge Power & Ground wires

There is a dedicated Fusible Link for the ECU
[1]id=26065

25230-C9900 RELAY ASSY [or 25230-C9907]
* SWITCH: 
  * C: BW wire from IGN switch
  * E: B ground/earth
* D SOURCE: from Brown fusible link to Light Green/white
* B OUTPUT: LgR to Red wire to ECU #207

factory wiring diagram

Fuel Pump Relays

At the minumum you need one relay for the fuel pump. It draws over 5 amps, so you don't want to run it directly through the IGN switch.

Although you could use one, for safety the Datsun factory system uses a chained system of three relays.

• Nissan 5-blade relay
• 25230-C9900, 25230-C9907 RELAY-FUEL PUMP JIDECO
• 25230-C9905 RELAY-FUEL PUMP NILES

Fuel Pump Relay 1

Pump On/Off: this relay engergizes the Fuel Pump and Air Regulator, but Relay 2 can open the circuit.

• SWITCH:
  • C: (Lg) from Fuel Pump Relay 2 OUTPUT (Lg)
  • E: Earth/ground
• D SOURCE: BW from IGN switch
• B OUTPUT: LgR
  • to Air Regulator LgR
  • to Fuel Pump LgR

Fuel Pump Relay 2

Pump Power: This relay is wired NORMALLY CONNECTED (i.e. when off). It passes on to Relay 1, but when Relay 3 is on it disconnects.

• SWITCH OFF:
  • C: L from ACC L FUSE 15A
  • E: (switched ground) LW from Relay 3 OUTPUT (LW)
• D SOURCE: BW from IGN switch
• A OUTPUT NORMALLY CONNECTED: Lg to Relay 1 SWITCH(Lg)

Fuel Pump Relay 3

Pump Cutout: This disconnects the Pump Feed relay in certain scenarios.

SWITCH: 
* C: BW from IGN switch
* E: WR to DIODE to Alternator WR
D SOURCE: YW to GROUND/EARTH via Oil Pressure Switch
B OUTPUT: LW to Relay 2 SWITCH (LW)

200SX Oil Pressure Switch is a dual-wire type because 200SX has an oil pressure gauge, but we only needs a regular sensor used on all A-series engines.

25070-80W0 DUAL OUPUT
* On/off pressure switch for OIL light & fuel pump relay
* Resistor sensor for gauge