Spark Plug: Service and Repair

Fig. 3 Intake Manifold Sensors And Left Plenum Support:

SPARK PLUG SERVICE
When replacing the spark plug and coil cables, route the cables correctly and secure them in the appropriate retainers. Failure to route the cables properly can cause the radio to reproduce ignition noise, cross ignition of the spark plugs or short circuit the cables to ground.

CAUTION: Do not attempt to adjust the gap of a platinum plug. Cleaning of the platinum plug may damage the platinum tip.

If carbon deposits must be removed, use a plug cleaner and complete cleaning within 20 seconds to protect electrode. Do not use a wire brush.

SPARK PLUG REMOVAL
Remove the spark plugs and examine them for burned electrodes and fouled, cracked or broken porcelain insulators.

Keep plugs arranged in the order in which they were removed from the engine. An isolated plug displaying an abnormal condition indicates that a problem exists in the corresponding cylinder.

SPARK PLUG REMOVAL - #2, #4 OR #6
Always remove the ignition cable by grasping at the spark plug boot turning, the boot 1/2 turn and pulling straight back in a steady motion.

1. Prior to removing the spark plug spray compressed air around the spark plug hole and the area around the spark plug.
2. Remove the spark plug using a quality socket with a rubber or foam insert.
3. Inspect the spark plug condition.

SPARK PLUG REMOVAL - #1, #3 OR #5
1. Disconnect negative cable from auxiliary jumper terminal.
2. Unplug connectors from MAP and intake air temperature sensors Fig. 3.
3. Remove plenum support bracket bolt located rearward of MAP sensor Fig. 3.
4. Remove bolt holding air inlet resonator to intake plenum Fig. 4.

Fig. 4 Air Inlet Resonator:

5. Loosen throttle body air inlet hose clamp.
6. Release snaps holding air cleaner housing cover to housing.
7. Remove air cleaner cover and inlet hoses from engine.
8. Unplug TPS and idle air control motor connectors Figs. 5 and 6.
9. Pry retainer tab back on throttle cable and slide cable out of bracket Fig. 7. Remove cable from throttle lever.
10. Slide Speed control cable out of bracket, if equipped Fig. 7. Remove cable from throttle lever.
11. Remove EGR tube from intake plenum Fig. 8.

Fig. 5 Throttle Sensor Position Sensor:

Fig. 6 Idle Air Control Module:

Fig. 7 Throttle Cable Attachment:

12. Remove plenum support bracket bolt located rearward of EGR tube Fig. 8.
13. Remove bolts holding upper intake plenum and remove plenum.

Fig. 8 EGR Tube And Right Manifold Support Bolt:

14. Always remove the ignition cable by grasping at the spark plug boot turning, the boot 1/2 turn and pulling straight back in a steady motion.
15. Prior to removing the spark plug spray compressed air around the spark plug hole and the area around the spark plug.
16. Remove the spark plug using a quality socket with a rubber or foam insert.
17. Inspect the spark plug condition.

Fig 2 Platinum Pads:

SPARK PLUG INSTALLATION

CAUTIONS:
- Extreme care must be used to prevent spark plug cross threading, mis-gapping and ceramic insulator damage during plug removal and installation.
- Never attempt to file the electrodes or use a wire brush for cleaning platinum plugs. This would damage the platinum pads which would shorten spark plug life.
- Apply a very small amount of anti-seize compound to the threads when reinstalling the vehicles original spark plugs that have been determined good. Do not apply anti-seize compound to new spark plugs.
- Anti-seize compound is electrically conductive and can cause engine misfires if not applied correctly. It is extremely important that the anti- seize compound doesn't make contact with the spark plug electrodes or ceramic insulator.
- Never force a gap gauge between the platinum electrodes or adjust the gap on platinum spark plugs without following the correct procedures.
- Always tighten spark plugs to the specified torque Over tightening can cause distortion resulting in a change in the spark plug gap. Over tightening can also damage the cylinder head. Tighten spark plugs to 28 Nm (20 ft. lbs.) torque.
- Due to the engine packaging environment for these engines. extreme care should be used when installing the spark plugs to avoid cross threading problems.

1. To avoid cross threading, start the spark plug into the cylinder head by hand.
2. Tighten spark plugs to 28 Nm (20 ft lb) torque.
3. Install ignition cables over spark plugs.
4. Install new gasket and position upper intake plenum. Tighten plenum bolts to 18 Nm (13 ft lb) torque.
5. Install bolts at plenum support brackets. Tighten bolts to 18 Nm (13 ft lb).
6. Install EGR tube to plenum. Tighten EGR tube to intake manifold plenum screws to 11 Nm (95 in lb).
7. Install throttle and speed control (if equipped) cables.
8. Attach electrical connectors to sensors.
9. Tighten air inlet tube clamps to 2-4 Nm (20-30 in lb) torque.
10. Connect negative terminal to auxiliary jumper terminal.