The 1998 Toyota 4Runner comes equipped with a distributor-less ignition system with some variations on different engine models. Under this system, the on-board computer controls the spark reaching the spark plugs through the coils. Although some coil-pack configurations still use spark-plug wires, other models, using the Toyota Direct Ignition (TDI) system, eliminated half of the plug wires or eliminated them completely. Still, replacing the coil packs on any of these systems is a pretty straightforward job.
Open the hood of your Toyota 4Runner and locate the label with the engine tune-up specifications. You may find this label on the upper radiator support or on the firewall, at the back of the engine compartment. Look for the engine model on the label. Also, you may also find it in your car’s owner's manual.
Remove the air-cleaner hose from the air-cleaner assembly using a Phillips screwdriver and a ratchet and socket.
Follow the spark-plug wires at the spark plugs to the other end where they connect to the ignition-coil packs, if you have a 2RZ-FE or 3RZ-FE engine model. Some 5VZ-FE and 2UZ-FE engine models also come equipped with spark-plug wires. If not, locate the coil packs on top of the left (driver's side) cylinder head.
Label the spark-plug wires connected to the coil packs you need to replace so that you can replace them in their correct order, if your particular model has the wires attached to the packs.
Disconnect the spark-plug wire from the first coil pack you intend to replace by pulling the wire from the boot. Twist the boot from side to side as you pull the wire off the coil pack.
Unplug the electrical connector from the coil pack.
Unfasten the coil-pack’s mounting bolts using a ratchet, ratchet extension and socket. Make a note of the position of each mounting bolt so that you reinstall the bolt in the same place.
Remove the coil pack from the vehicle.
Set the new coil pack in place and hand-tighten the mounting bolts.
Tighten the mounting bolts to 84 inch-lbs. (10 Nm), if you have a 2RZ-FE or 3RZ-FE engine model, or 69 inch-lbs. (7.8 Nm), if you have a 5VZ-FE or 2UZ-FE engine model. Use a torque wrench.
Coat the inside of the spark-plug wire’s boots with dielectric grease using a flat-head screwdriver.
Connect the spark-plug wire to the coil pack and make sure the boot snaps over the coil-pack tower connector, if your model is equipped with spark-plug wires.
Plug the electrical connector to the coil pack. Replace other coil packs following the steps above.
Replace the air-cleaner hose on the air-cleaner assembly using a Phillips screwdriver and a ratchet and socket.
Start the engine and make sure it works properly. Then turn off the engine.
