1991 Jeep Cherokee LimitedFACTORY OEM SERVICE PROCEDURE

Idle Speed & Ignition Timing Check

Ensure idle speed and ignition timing are set to specification. See CURB IDLE SPEEDΒ  and IGNITION TIMINGΒ  tables. For adjustment procedures, see ADJUSTMENTS article in tion\tion.

NOTE: Curb idle speed and ignition timing on 2.5L and 4.0L are controlled by the Single-Board Engine Controller II (SBEC-II) and are not adjustable.
CURB IDLE SPEED

Application Idle RPM
5.9L 600
IGNITION TIMING

Application (Degrees BTDC @ RPM)
5.9L 16 @ 600
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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.