1987 Mitsubishi Montero Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Mixture Control Valve

Check valve after engine is warmed to operating temperature. Remove air filter. Start engine and open and close throttle valve quickly. Mixture control valve should pop out once and quickly close. Air suction noise should be heard. With engine at idle, valve should remain closed and no air suction should be heard.

Fig 1: Deceleration Spark Advance System
G65431Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Factory Service Tools

Use the Manual With the Right Hardware

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

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

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.