G13B Engine

Which Haltech ECU?

Any Elite model can run the G13B. For a simple, naturally aspirated build the smaller Elites have plenty of I/O; step up if you're adding boost control, a wideband or extra sensors. Browse the Elite range or ask us which fits your plans.

Engine basics

The trigger: modify the distributor first

The factory distributor uses a reluctor pickup reading a 12-tooth wheel. The teeth sit in four groups of three, and nothing in the pattern tells the ECU which cylinder is next. That arrangement is unique to this engine and no Haltech ECU supports it as-is.

The fix is mechanical: in each group of three, remove the two smaller teeth and keep the large one. You end up with four evenly spaced large teeth, which the ECU can use.

If reluctor pickups are new to you, see Hall effect or reluctor and distributor rotor phasing, which matters any time a distributor still carries the spark.

Ignition: coil with an external igniter

The coil is fired by a separate igniter module, so the ECU sends a logic-level signal rather than driving the coil directly.

Set the ignition to Constant Charge with a Falling edge. Dwell should suit the OEM coil and igniter; dwell time explains the setting. Getting the edge wrong can hold the coil on and cook it, so double-check before you connect the coil.

Sensors and actuators

Throttle position

The throttle is cable operated with a four-pin position sensor.

MAP

There's no factory MAP sensor. The ECU's internal sensor is fine for a naturally aspirated or low-boost setup; for more boost, fit an external sensor such as the 3 bar GM MAP sensor on a spare AVI.

Idle air

Idle is handled by a 2-pin bypass air control valve, duty-cycled by one ECU output. Polarity doesn't matter.

• Pin 1 (open signal): any spare output.
• Pin 2 (power): switched +12V.

Coolant and air temperature

The coolant sensor lives by the thermostat housing. There's no factory air temp sensor, so add one, for example Haltech's air temp sensor. Both are two-wire and not polarity sensitive: one pin to a spare AVI, the other to Signal Ground.

Use an AVI with a selectable pullup turned on. If yours doesn't have one, add an external 1k pullup to 5V. Haltech's temperature calibrations for these assume that 1k pullup.

MAF (optional)

Most people delete it, but if you want to keep it: pin 1 no connection, pin 2 switched +12V, pin 3 sensor ground, pin 4 to a 0-5V AVI.

Oxygen sensor

The stock sensor is a single-wire, unheated narrowband, which is no use for tuning. Replace it with a Haltech CAN wideband, such as the WB1 kit. The sensor is reached from underneath and takes a 22 mm socket or wrench.

Vehicle speed

Speed comes from a Hall effect sensor in the instrument cluster, driven by the speedo cable, with a single signal wire to the ECU.

Injectors

The factory ECU supplies both power and ground to the injectors, but the wiring merges both power feeds and both signal wires, so all four fire together. When you wire the Haltech, give each injector its own output rather than copying the factory's shared wiring.

• Flow: 200 cc/min, measured at 100% duty.
• Resistance: 2.2 ohm, so set injector current control to Low.

If your fuel pressure isn't referenced to manifold pressure, map the injector flow against manifold pressure so the ECU compensates properly.

Factory ECU and base map

The OEM ECU sits on the left side of the dash. Haltech has an Elite 550 base map for the G13B built from this information and their default map. Treat it as a starting point: confirm the trigger, ignition and injector settings before loading it, because wrong values can damage the coil, igniter or ECU.

Need the OEM ECU pinout, the tooth diagram or the base map? Ask us and we'll send them over with advice for your build. For other engines, see our Suzuki M16A page or the knowledge base.