Basic Idle Adjustment

Basic Idle Adjustment

To set your idle you will need a couple basic hand tools:

  • A Phillips head screw driver
  • A digital multi-meter
  • A drill & small drill bit (If this is your first time adjusting it)
  • A short flat edge screw driver
  • A ½" combination wrench
  • A 7/16" combination wrench

Now let's get started here. To start off what you need to do is start your car & let it warm up thoroughly. With the car at operating temperature, remove the electrical connector to the IAB (idle air bypass). The IAB is mounted to the front of the throttle body with two small bolts. It looks like long silver cylindrical tube with a mounting flange. To remove the connector simply pry up the securing clip gently & firmly pull the plug out. You should notice a slight drop in idle RPM when the IAB is disconnected.

With that done you can move to the throttle body to adjust the throttle stop screw. Standing on the passenger side of the vehicle, reach down the rear most part of the throttle body & feel for the throttle stop. Once you locate the throttle screw you may turn it with the short flat blade screwdriver RPM up or down. There is a jam nut usually affixed to the throttle stop screw to prevent the screw from backing out. This nut typically requires a 7/16" combination wrench to loosen. To adjust the RPM up turn the screw in, to adjust it down turn the screw out. I have found the best idle stability to be at, or around 850-900 rpm. This will vary according to any modifications you have done, particularly any aftermarket camshafts.

Once you have achieved your desired idle RPM you will need to reset the TPS setting to ~.97 volts. Sometimes adjusting the TPS to the correct range will alter idle RPM, so it may be necessary to repeat the procedure until the desired idle RPM is achieved. After this is complete you may reconnect the IAB & shut the vehicle off. At this point you will need to reset the EEC so that it may adjust to the new idle settings. To do this, disconnect the negative battery cable from the battery using the ½" combination wrench. You will need to leave it disconnected for 15minutes, after which you can reconnect the negative terminal of the battery. Congratulations you have just reset your idle speed setting.

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