1987 Mitsubishi Starion ESI-RFACTORY OEM SERVICE PROCEDURE

Motor Position Sensor (MPS)

The motor position sensor is installed in the ISC servo. It is a variable resistor type sensor. The MPS senses ISC servo plunger position and sends a signal to ECU. The ECU then controls throttle valve opening and idle speed.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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