Mazda MX-5 NA does not keep running after fitting ME221/442 standalone ECU

In older generations of the Mazda MX-5 NA, the Air Flow Meter (AFM) also controls the operation of the fuel pump. With Motorsport Electronics’ advanced standalone ECU, however, it is possible to install an intake temperature sensor (IAT), making the AFM unnecessary.

If you don’t go through the manual thoroughly, you may run into a problem: the MX-5 will start, but will stall again after a few seconds, or refuse to start completely.

Does this scenario sound familiar to you?

Below is the solution:

• “Quick and dirty”
  Do you want to move on quickly? In the diagnostic box at the left strut tower, connect the contact F/P to GND using a wire or piece of iron.
  
  REMEMBER!!! This is a temporary solution. In the event of an accident, the fuel pump continues to run.
  
• The right approach:
  Look for the fuel relay near the steering column. Next, connect pin 2T of the ECU to the cable that runs from the diagnostic box at the left strut tower to this fuel relay. Through this connection, the ECU will determine when to activate or deactivate the fuel pump.