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[Datsun 1200 encyclopedia]


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Categories: Fuel System | Fuel Injection

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Revision as of 15:04, 19 June 2024
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* Control unit ([[ECU]]) * Control unit ([[ECU]])
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* Fuel damper & Fuel pump. Similar or same as 280ZX part. * Fuel damper & Fuel pump. Similar or same as 280ZX part.

Revision as of 15:04, 19 June 2024

You can fit the 1980-1983 Nissan 200SX EGI System to your Datsun 1200. Get all the parts if you wish to do this conversion: From the fuel pump to the relays and all the wiring harnesses, etc. Use the air-flow meter and ECU from the S110, and an A-series EFI manifold from a B310.

400px-Silvia2000ZSE-X_04.jpgWIKI go to Wikipedia 400px-S110_Silvia.jpgWIKI go to Wikipedia



You need all the parts listed below. There are a LOT of parts (as with any EFI system). This includes the pressure fuel pump & filter. Obtain as many of the parts as you can from a donor S110.

You can use either the S110 parts or the B310 parts, or a mixture. Additionally, many of the parts are available on the 280ZX such as injectors, sensors and fuel pump. See the EGI article for more details on specific parts.

The 200SX parts can be used with some bracket-mounting modifications for the A-series factory EFI manifold. The Z-series (Z20/Z22 engine) manifold is very similar, except of course for the specific bolt pattern.

A-series EGI manifold
939.jpgAlbum 939
See the EGI main article for information about this manifold.

Compare to L-series EFI manifold. Same design, but runner flanges suit L16/L18 engine
7486.jpgAlbum 7486

EGI System diagram

It would be best to use the wiring and sensors from an A14E or A15E engine (Asian-market B310). If you buy a B310 inlet manifold, it will typically come with most of the needed parts. There are additional parts (e.g. airflow meter, cylinder head temp sensor, and fuel pump) needed but since those are virtually non-existent in USA, you can use the 200SX parts.

EGI System Schematic

1981 200SX Underhood parts location

Don't forget the Fuel Check Valve

Existing Articles

Tens & Twenties has written an interesting article on fitting this Nissan EFI system into other cars. This is from the 1980 200SX (aka S110/Sylvia/Gazelle) with Z20E engine.

this set-up will run just about any 4 cylinder in the world ... And it's easier than you think.  ;^)

A link to his original article is below (see More Information section).


Fuel pressure (after fuel filter)
* 30 psi at idle
* 37 psi at Initial full throttle
Fuel pump
* 43-64 psi Cut-off discharge pressure
* 5.1 amps Design current
Pressure regulator
* 36.3 psi
Air regulator
* 671 cu ft/hr Air flow (@68 F/20 C)
* 25-90 ohms heater coil resistance
Fuel injector
* 2.35 ohms coil resistance
Vacuum switch
* 6.30 in Hg - intake vacuum when switch turns on

System Parts

Many of these parts are included with a used A-series EFI manifold. See EGI for details and/or part numbers.
2950.jpgAlbum 2950


Anti-Clockwise from top:

  • Injector - usually included with used Manifold
  • Pressure Regulator - generally included with used Manifold
  • Fuel Filter - same as 280Z & 280ZX. Any EFI (high pressure) filter may be used
 Nissan EFI 1975-1997
 * BECK/ARNLEY 0430165
 * WIX 33022
 * FRAM G7404
  • Air regulator - generally included with used Manifold
  • Throttle chamber - generally included with used Manifold
 * Dash pot
 * Throttle valve switch
 941.jpgAlbum 941
  • I.A.S. unit - generally included with used Manifold
  • Air flow meter with Air temperature sensor. IMPORTANT: get the AFM that matches the ECU.

airflow_meter.jpg a14E_meter.jpg 22680-H9200.jpg airflow_meter_.jpg

  • Dropping resistor


  • Cylinder head temperature sensor

22630-N4200.jpg see ECU Temperature Sensor

  • Exhaust gas sensor (U.S.A. models) a.k.a. O2 Sensor only used by 1982-1983 ECU
  • Control unit (ECU)

29706.jpgAlbum 29706

  • Fuel damper & Fuel pump. Similar or same as 280ZX part.

21845.jpgAlbum 21845

Other Parts

Air Filter
* FRAM CA4303
* BECK/ARNLEY 0420810
* WIX 42136
  * Height 1.416 
  * Width 6.198 
  * Length 10.710 
  * CFM 210
Fuel Check Valve
  * 720 0780-1280 K/CAB.2WD, T.REG.2WD, T.LONG.2WD+HD/T
  * 720 0679-0680 T.REG, T.LONG+HD/T, K/CAB
  * 910 0780- W.L24E + W.LD28, LD28.MT.F5 + S.LD28.AT + S.L24E
  * S110 0179- (FED.HT+CAL.HT)Z20E+FED.HT.Z
EFI vacuum switch

Air Cleaner & Airflow sensor
174_4c81aa92e4df2.jpgUpload click to view 20100814%20191910%20DSC00492.jpg

Ignition Coil & Distributor

1979-up systems use a 12 volt primary coil (no ballast resistor is used).

Coil Specifications
modelTypePrimary resistanceSecondary resistance
1980 CaliforniaCIT-381.04 to 1.27 ohms7.3 to 11.0 ohms
1980 49-state and CanadaCIT-300.84 to 1.02 ohms8.2 to 12.4 ohms
1981 US (all)CIT-461.04 to 1.27 ohms7.3 to 11.0 ohms
*Resistence measured at @ 68 F (20 C)

The 200SX uses a typical Electronic Ignition distributor, with the same control box as the USA B310 distributor. But you don't need this, it won't affect the EFI system. A points distributor will work fine as long as you replace the point set every 12 months.

3518.jpgAlbum 3518

High-Pressure Fuel filter replacement

The fuel filter is attached by a bracket to the right shock well. Be sure to replace with a specific high-pressure equivalent

Before disconnecting the fuel lines from the filter, the pressure in the fuel system must be reduced to prevent dangerous spraying. This is done in the following manner:

  • Locate the fuel pump relay-2 attached to the engine compartment relay bracket. The bracket must be removed from the body in order to gain access to the relays

Fuel pump Relay-2

  • Start the engine and allow it to idle
  • With the engine running, disconnect the wiring connector for fuel pump relay-2. NOTE: Wires to this relay are light green, blue, blue/white stripe and black/white stripe.
  • Wait for the engine to stall, then crank the engine over 2 or 3 times
  • Turn the ignition switch off and reconnect the wiring connector to the fuel pump relay-2. Reconnect the relay bracket.

After the fuel pressure is bled off:

  • Disconnect both fuel lines from the fuel filter and lift the filter out of its bracket
  • When connecting the fuel lines to the new filter, use hose clamps and position them 3mm from the ends of hose.

General Description

The Datsun NAPS-Z engine uses and Electronic Fuel Injection (EFI) fuel system in place of the conventional carburetor-type system. Electronic fuel injection provides continous optimum mixture ratios at all stages of combustion. It uses a Hitachi L-Jetronic system licensed from Bosch, so it has good German engineering. It is an EFI system similar to modern systems except for its use of an airflow vane meter. Systems now use either Speed-Density (calculated airflow) or Mass Airflow (solid-state flow meter). That being said, the airflow meter makes good power and is adjustable, and worked well on millions of VWs and even powerful Porsches.

The EFI system consists of three sub-systems:

  • fuel flow system
  • air flow system
  • electrical signaling system

Fuel Flow System Fuel from the tank is delivered at about 36 psi. To minimize pulsing it goes through a mechanical damper. The regulator maintains a constant pressure difference between the fuel line pressure and the intake manifold vacuum. Excess volume and pressure is returned to the tank via the return line.

Injection occurs once every engine rotation. All four injectors operate simultaneously and independent of the engine stroke. Each injector supplies half the amount of fuel required by the cylinder. The length of the injection period is determined by the control unit after consulting all the various input sensors, such as RPM, throttle position, air temperature, manifold vacuum, etc.


Three relays are used for the fuel pump. This system is designed to prevent pumping if the engine stops running. Apparently there is a relay for Ignition, fuel pressure and oil pressure. Loss of any of these signals will stop the pump.

See main article: EFI Wiring

Fuel Pump Relays
20100829190310DSC00748x.jpg 20100829190733DSC00757x.jpg

Electrical Signaling System The 1980 system does not use an oxygen sensor, but the 1981 model does.

1981 200SX Wiring

Injector Wiring for the 1981 ECU:

Also see EGI Wiring for more information.
Quickie wiring chart
wire colorconnects to
YELCoil Neg.
REDGRN/BLK (of relay)
(relay) GRN/WHTBATT+
(relay) BLKGround/Earth
(relay) BLK/WHTIGN "on"

When you buy an ECU it is critical to get at least a bit of the ECU wiring connector with a few inches of the wiring, since it is a special connector. If you only got a bit of the wiring you will need to locate the sensor wires and wire those up (including Injectors, Temp, IAC, TPS, MAP, air temp, Airflow Meter). If you get the entire harness it will already have these figured out.

More Information