Motec M84 ECU

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  • Regular price £1,422.00 (Ex-vat : £1,185.00)

Stock status: Not in Stock - You can still order this item, if you order today we expect to have the item ready for shipping in : 3-5 Days

*SPECIAL ORDER ITEM* - Click to learn more

The Motec M84 is a versatile, race-bred ECU that is suitable for a broad range of high performance applications, including engines with up to 8 cylinders. It also suits rotary engines with twin, triple or quad rotors. 

This new, entry level ECU is based on the advanced technology in MoTeC's benchmark M800, with a package of features to suit more moderate system requirements. It includes on-board Wideband Lambda plus 1 MB of data logging memory as standard.

Install it as a stand-alone ECU or as part of a complete motorsport-ready engine management and data acquisition solution. 



  • 8 x Injector outputs - high or low ohm

  • 6 x Ignition outputs

  • 8 x Auxiliary outputs - for functions such as boost control, idle speed stepper motor and many more


  • Throttle Position

  • Manifold Pressure

  • Mass Air Flow
  • Fuel Pressure
  • Oil Pressure
  • Exhaust Temperature
  • Gear Position
  • User 1
  • Air Temperature
  • Coolant Temperature
  • User 2
  • 3 x Switched Analogue Temperature
  • 2 x Lambda Inputs (supports Wideband and Narrowband sensors)
  • 4 x Digital Inputs (wheel speed or switch)


  • 1 x CAN

  • 1 x RS232


  • Case size 147 x 105 x 40 mm
  • Weight 500 grams
  • 1 x 34 pin and 1 x 26 pin waterproof connector with gold plated contacts

Engine Tuning Features

  • Windows based ECU Manager tuning software with user definable screen layouts

  • Individual cylinder tuning of both fuel delivery and ignition timing

  • Suits modern engines, including those with coil per cylinder ignition

  • Fully configurable axis points on all tables

  • Highly configurable crank and cam trigger inputs to suit almost all OEM sensors and tooth patterns
  • Single Wideband Lambda input (dual optional)

Additional Distinct Features

  • Capable of advanced control functions, such as:
    • Traction control
    • Overrun boost enhancement (anti-lag)
    • Gear change ignition cut (flat shift)
    • Boost control
    • Nitrous injection
    • Dual stage injection (Hi/Lo injection)
  • Configurable sensor inputs including custom calibrations
  • Capable of receiving and transmitting data via the CAN bus 
  • Capable of receiving data from two Lambda measurement devices via CAN
  • Integrated advanced diagnostics, including injector and crank trigger diagnostics
  • Ref/Sync capture displayed on the built-in digital oscilloscope

Data Acquisition

  • Internal data logging (1 MB) with fast download via CAN
  • State of the art i2 Standard data analysis software
  • Now with 100 Hz max logging rate

Note1: Celica ST185 & MR2 Turbo Rev 1 & 2 also require a Comms lead, 3 bar map sensor, air temp sensor & boost control valve.

Note 2: Celica ST205 & Rev 3 MR2 Turbo only require a Comms lead, all other sensors will work.

Note 3: Starlet EP82/91 also require a Comms lead, 3 bar map sensor, throttle position sensor.

All cars - future mapping costs £75 + vat per hour. (minimum charge 2 hrs)

We can supply a M84 ecu with wiring instructions and a base map for self installation. 

All Car -Notes:

Please help us with the following, this will ensure a quicker turnaround for you

We expect the vehicle to be in a legal roadworthy condition, fully serviced and for it to be prepared as you would for a rolling road session.

For higher boost than std , please make sure all vacuum/boost pipes and connections are secure and that fuel system is in good condition.

Whilst mapping a wideband lambda sensor is used in the exhaust system, therefore all joints and gaskets must be leakfree ahead of the sensor.

Your vehicle is insured against theft/total loss whilst in our possession up to £25,000, if your vehicle is genuinely worth more than this amount - please let us know so that extra cover can be arranged at your expense.

Racing cars can be mapped at Blyton Park, we can also map on engine dynos and rolling roads, please enquire about costs.

A disclaimer must be signed before any work can commence, please e-mail us if you wish a copy of this in advance.

Why Motec:(not technical)

Well it all started back in 1996, with our first 3sgte conversion into a corolla, we needed an ecu that could be programmed and was suitable for road use. Most people then believed these "black magic boxes" were for racing cars only, I remember one guy telling me "just run the fuel pump via an oil pressure switch mate, it will take longer to start and not be too good if your upside down under a tree somewhere, but it`ll work ok - ish"

Motec being Australian owned seemed like the best option, Australia have different modifications and emissions laws to us, for this reason they had a better understanding of what the road car market required. In blunt the ecu could control almost anything and was very road car friendly, it was also a bonus that motec europe was also run by ex TTE staff, so at least there was all the backup needed back then in the early days.

That first corolla covered 59,000miles and never missed a beat, so when the second corolla was built, a motec was installed and off it went and done 54,000 miles and never missed once, it always started even in -20 in Scotland, it always ran round the M25 with no fuss at all, this car is now competing in the Mauritius rally championship so its starts good when its hot too!

The 3rd corolla - well that's still being developed, currently over 650bhp, has already covered 39,000 miles some of them extremely quickly. Because of this constant development program, we now have our own mapping specialist here in house who has been trained over many years with the 3sgte engine and also has full backup from Motec.

Virtually all Fensport cars now run Motec, the reason for this is its unrivaled, when you look at the whole picture. Yes there are piggybacks and other ecu`s out there, but as an overall package the motec is a very suitable ecu for our needs, its software can be upgraded for free, its supported by many tuners all over the uk and the world, it can grow with your budget, its simple to install and the software is very user friendly, it can be used on a std road car to a wrc car.

It can initially seem more expensive than the cheaper alternatives, but remember to add all the other costs these cheaper systems may need like wiring looms, temp sensors, cam sensor, tdc sensor, the extra cost of fitting these and also the mapping costs of cheaper systems need to taken into consideration.

For technical details please see

Motec ECU's are not held in stock, they are delivered on a next working day basis.

Please check out our Motec section in "Fensport Cars" to see some of the projects we have been involved with.

Note: We still support the Motec M4 & M48 Ecu

  • Special order
  • Toyota Celica GT4 ST165 01/88> 12/90
  • Toyota Celica GT4 ST185 10/89> 03/94
  • Toyota Celica GT4 ST205 02/94> 08/99
  • Toyota MR2 Turbo Rev 1 3S-GTE 12/89> 12/91
  • Toyota MR2 Turbo Rev 2 3S-GTE 12/91> 11/93
  • Toyota MR2 Turbo Rev 3 3S-GTE 11/93> 08/99
  • Toyota Starlet 1.3 Turbo EP82 4E-FTE 12/89> 12/95
  • Toyota Starlet 1.3 Turbo EP91 4E-FTE 01/96> 12/99

No notes available