Engine Controls - Removal & Installation: Diagnosis Pontiac Aztek I

Inspection

1. Ensure that the correct spark plug is installed. An incorrect spark plug causes driveability conditions. Ensure that the spark plug has the correct heat range. An incorrect heat range causes the following conditions: Spark plug fouling - Colder plug. Pre-ignition, causing spark plug and/or engine damage - Hotter plug.
2. Inspect the terminal post for a bent or broken terminal post. (Scheme 6) Test for a loose terminal post by twisting and pulling the post. The terminal post should not move.
3. Inspect the insulator for flashover or carbon tracking, soot. This is caused by the electrical charge traveling across the insulator between the terminal post and ground. Inspect spark plug boot for damage. Inspect the spark plug recess area of the cylinder head for moisture, such as oil, coolant, or water. A spark plug boot that is saturated causes arcing to ground.
4. Inspect the insulator for cracks. All or part of the electrical charge may arc through the crack instead of the electrodes. Inspect for evidence of improper arcing. Measure the gap between the center electrode and the side electrode terminals.
5. Inspect for the correct spark plug torque. Insufficient torque can prevent correct spark plug operation. An over-torqued spark plug causes the insulator to crack.
6. Inspect for signs of tracking that occurred near the insulator tip instead of the center electrode. Inspect for a broken or worn side electrode. Inspect for a broken, worn, or loose center electrode by shaking the spark plug. A rattling sound indicates internal damage. A loose center electrode reduces the spark intensity.
7. Inspect for bridged electrodes. Deposits on the electrodes reduce or eliminates the gap. Inspect for worn or missing platinum pads on the electrodes, if equipped. Inspect for excess fouling. Inspect the spark plug recess area of the cylinder head for debris. Dirty or damaged threads can cause the spark plug not to seat correctly during installation.
8. Brown to Grayish-Tan with small amounts of White powdery deposits are normal combustion by-products from fuels with additives. Carbon fouled - Dry, fluffy, black carbon, or soot is caused by rich fuel mixtures such as leaking fuel injectors, excessive fuel pressure, restricted air filter element and incorrect combustion. Reduced ignition system voltage output which includes weak coils, worn ignition wires and incorrect spark plug gap can also cause carbon fouling.
9. Excessive idling or slow speeds under light loads can keep spark plug temperatures so low that normal combustion deposits may not burn off. Deposit fouling - oil, coolant, or additives that include substances such as silicone, very White coating, reduces the spark intensity. Most powdery deposits will not effect spark intensity unless they form into a glazing over the electrode.

Scheme 6

1. Gap the spark plugs to specification. See «SPARK PLUGS»(ref-151523-S16272079062002123000000) under IGNITION SYSTEMS in SERVICE & ADJUSTMENT SPECIFICATIONS - 3.4L AZTEK & RENDEZVOUS article. Install the spark plugs. Tighten the spark plugs to specification. See «TORQUE SPECIFICATIONS»(ref-155806-S21244843402003062600000) .
2. Install the spark plug wires to the spark plugs. Return the engine to the proper position. Remove the engine tilter strap from the engine. Swing the engine mount struts in position. Install the engine mount strut bolts and tighten bolts to specification.

1. Remove the spark plug wires (2, 4, and 6) from the front bank (bank 1) spark plugs. Remove the spark plug wires from the retaining clips. Set the park brake. Shift the transaxle into Neutral. Remove the engine mount strut bolts. see scheme 28
2. Swing the engine mount struts aside. Install the Engine Tilter Strap (J-41131) to the engine. see scheme 29 Pull on the engine in order to rotate the engine forward. Tighten the engine tilter strap.
3. Remove the spark plug wires (1, 3, and 5) from the rear bank (bank 2) spark plugs. Remove the spark plug wires from the retaining clips. Remove the spark plug wires from the ignition coils. Remove the spark plug wires from the engine. (Scheme 7)and (Scheme 8). If you are replacing the spark plug wires, transfer the boot heat shields, spark plug wire conduit and spark plug wire retaining clips.

Spark plug wire integrity is vital for proper engine operation. A thorough inspection will be necessary to accurately identify conditions that may affect engine operation. Inspect for correct routing of the spark plug wires. Improper routing may cause cross-firing. Inspect each wire for any signs of cracks or splits in the wire. Inspect each boot for the following conditions

1. Tearing.
2. Piercing.
3. Arcing.
4. Carbon tracking.
5. Corroded terminal.

If corrosion, carbon tracking, or arcing are indicated on a spark plug wire boot or terminal, both the wire and the component connected to the wire should be replaced.

1. Install the spark plug wires to the engine. Install the spark plug wires to the ignition coils. see scheme 27 Install the spark plug wires (1, 3, and 5) to bank 2 spark plugs. Install the spark plug wires to the retaining clips.
2. Return the engine to the proper position. Remove the engine tilter strap from the engine. Swing the engine mount struts in position. Install the engine mount strut bolts and tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-155806-S21244843402003062600000).
3. Install the spark plug wires (2, 4, and 6) to bank 1 spark plugs. Install the spark plug wires to the retaining clips.

Scheme 7

Scheme 8