3 and 6 ignition coil do not fire

ignition will trigger if signal from crank sensor, with hei spark plug tester ,read to coil wire and spark plugs wire if spark , depends wich engine
if c3i coil and module the module could be the problems you can check it before replace
hope it helps

Hi,
Check the ignition distributor cap and clean the electric contact points it might be already dirty.

if one has a spark that means your ignition coil is still okay. Remove the whole cap and check the inside part and clean it, use emery board.
Check also the high tension wires( spark plug wires ).
Hope Fixya helps you!

Have you checked the spark plug itself? --- 5.7L Engine To Remove:
NOTE: Note spark plug cable original positions before removing.

1. Before servicing the vehicle, refer to the precautions at the beginning of this section.
2. Clean the area around the coil with compressed air.
3. Remove or disconnect the following:
   • Battery negative cable
   • Throttle body air intake tube and intake box (if necessary)
   • Coil electrical connector by moving slide lock and pressing on release lock
   • Secondary high-voltage cable from coil
   • Mounting bolts
   • Coil from cylinder head opening by twisting

To Install:

1. Clean area around spark plugs with compressed air.
2. Apply dielectric grease to inside of boots.
3. Install or connect the following:
• Ignition coil to cylinder head opening
• 2 mounting bolts
  1. Torque to: 106 inch lbs. (12 Nm)
• Coil electrical connector
• Cable to coil
• Throttle body air tube and intake box (if necessary)
• Battery negative cable

---
Distributorless Ignition System General Information This vehicle uses two different types of ignition systems. The 3.7L, 4.7L, and 5.7L engines do not use a conventional distributor. The 5.9L engine uses a conventional distributor. The ignition system is controlled by the Powertrain Control Module (PCM) on all engines. Procedures in this section are for the 3.7L, 4.7L, and 5.7L engines; please see the section on Distributor Ignition Systems for procedures for the 5.9L engine.
Distributorless ignition systems (EI) are used on many current engines. This system uses the waste spark method for distributing secondary voltage. In a waste spark system, an individual coil is used to fire one pair of engine cylinders simultaneously. These cylinders are known as companions, since each of their pistons is at TDC at the same time. On a typical V6 engine for example, cylinder 1 is at TDC compression while cylinder 4 is at TDC exhaust. This is also true of cylinders 2 and 5 as well as cylinder 3 and 6.
The cylinder on the compression stroke is known as the event cylinder, while the cylinder on the exhaust stroke is called the waste cylinder. Since secondary resistance is very low in the cylinder on the exhaust stroke, little voltage is required to fire the plug. For this reason, the majority of available voltage is consumed by the cylinder on the compression stroke.
One spark plug is attached to each end of the secondary coil winding via the spark plug wires. This series circuit arrangement causes one of the plugs to fire in a forward direction (center electrode to outer electrode), and the other spark plug to fire in a reverse direction (outer electrode to center electrode). The firing voltage requirements on the waste spark ignition are significantly greater than a traditional ignition system primarily because it takes 30% more energy to fire a plug reverse polarity. When a spark plug is fired backwards, it fires from the outer electrode to the center electrode. This is a high resistance path since the electrons do not flow as easily from a cold, dull surface such as the outer electrode to a hot, sharp surface like the center electrode.
Since the coil and plugs are arranged in a series circuit, a typical plug gap of .050" results in a total gap of .100" for the whole circuit that includes two spark plugs for the companion cylinders. The waste spark can overcome this added resistance by producing high secondary output voltages due to low resistance in the primary winding. Another reason higher secondary ignition voltage is required is cylinder pressure; specifically, the lack of it. Generally, event cylinders require 10 to 12-kV to initiate current flow across the spark plug gap, while only 2 - 3-kV is needed to fire the waste cylinder. Therefore, the air gap in the waste cylinder creates no more resistance than the rotor gap does in a conventional ignition system.
There are two different methods used for coil trigger. One method sends the crankshaft sensor signal directly to the ignition module to activate the coils, while the other sends the crankshaft sensor signal to the PCM and the PCM controls ignition operation either directly or through a separate ignition module.
Waste spark ignition advantages

• It has fewer components than conventional distributor-type ignition systems.
• No mechanical adjustments to set ignition timing.
• No mechanical load (turning the distributor shaft).
• No unwanted timing variations caused by gear lash or other worn distributor components.

Another advantage of waste spark is longer coil life. To illustrate this point, consider a six-cylinder engine with conventional ignition. At 3000 RPM, the coil must fire 9000 times per minute. This is calculated by dividing the engine speed by 2, since the cam turns at half crank speed, and then multiplying the distributor RPM by the total number of engine cylinders.
In contrast, the coils on a six-cylinder engine with waste spark only work a third as hard. This is because there's a coil for every two cylinders and each coil fires every crankshaft revolution. This means that at 3000 RPM, the coils only fire 3000 times per minute. This allows each coil to operate with less dwell (time that the coil is energized), resulting in less heat buildup and longer life.
Coil Over Plug System The coil over plug system was developed so that spark and spark timing could be better controlled on an individual cylinder basis. Each cylinder has an ignition coil mounted directly above the spark plug on the cylinder head cover. A short suppresser/connector replaces the spark plug wire and links the coil to the plug. There are different methods used for primary triggering. Some manufacturers use a combination coil/module, which means each coil has its own control circuit that is activated by the PCM. Others use remote mounted modules to trigger the coils.
Each individual coil is allowed to saturate while all other cylinders fire. For a V-8 engine, this allows a period of seven firing events for coil saturation, compared to three events for the same V-8 engine with a waste spark system. The coil over plug system also benefits from a minimum amount of energy lost, due to the resistance of spark plug wires.
Coil Near Plug System The coil near plug system also features multiple ignition coils. An ignition coil/module is mounted in proximity of each cylinder. There is a short length of spark plug wire between the coil and the spark plug.
Each ignition coil/module has its own control circuit and is activated sequentially by the PCM. All timing decisions are made by the PCM. This includes both ignition timing and duration of the spark.

2003 Chevrolet Malibu 3.1L SFI OHV 6cyl
Spark Plug Wires - Removal & Installation

3.5L Engine

1. Before servicing the vehicle, refer to the Precautions Section.
   NOTE Twist the spark plug boot one-half turn in order to release the boot. Pull on the spark plug boot only. Do not pull on the spark plug wire or the wire could be damaged.
2. Remove the intake manifold cover, if required.
3. Disconnect the left side spark plug wires from the spark plugs.
4. Disconnect the left side spark plug wires from the ignition coil.
5. Remove the spark plug wire clips from the Manifold Absolute Pressure (MAP) sensor bracket and the heater inlet and outlet pipe tab.
6. Remove the spark plug wire assembly.
7. If replacing only one plug wire, open the retaining clips and remove the appropriate spark plug wire.
8. Disconnect the right side spark plug wires from the spark plugs.
9. Disconnect the right side spark plugs from the ignition coils.
10. Remove the spark plug wire assembly.
11. If replacing only one plug wire, open the retaining clip and remove the appropriate spark plug wire.

To install:

1. Install the spark plug wire assembly.
2. Connect the right side spark plugs to the ignition coils.
3. Connect the right side spark plug wires to the spark plugs.
4. If replacing only one plug wire, open the retaining clip and install the appropriate spark plug wire.
5. Install the spark plug wire assembly.
6. Connect the left side spark plug wires to the spark plugs.
7. Connect the left side spark plug wires to the ignition coil.
8. Install the spark plug wire clips to the MAP sensor bracket and the heater inlet and outlet pipe tab.
9. If replacing only one plug wire, open the retaining clips and install the appropriate spark plug wire.
10. Install the intake manifold cover, if required.

Fig. 2.2L Engine Firing Order: 1-3-4-2 Distributorless ignition system



Fig. 3.1L Engine Firing order: 1-2-3-4-5-6 Distributorless ignition system



Fig. 3.5L Engine Firing order: 1-2-3-4-5-6 Distributorless ignition system



Fig. 2.4L Engine Firing order: 1-3-4-2 Distributorless ignition system



Fig. 3.1L Engine Firing order: 1-2-3-4-5-6 Distributorless ignition system



Fig. 2.2L Engine Firing Order: 1-3-4-2 Distributorless ignition system


Fig. 3.5L & 3.9L Engines Firing order: 1-2-3-4-5-6 Distributorless ignition system


I really hope help you with this (remember rated this help) Good luck.

The mechanic should check on the ignition system first . Check the ignition switch, the ignition coil , the spark plug , the spark plug cable , the distributor assembly and the wires and the fuses.Check if there are worn out or destroyed then replace it. And then set the distributor timing mark and the firing order of the spark plug which is 1,3,4,2.These 1,3,4,2 are the number of the spark plug connecting to the distributor assembly.Then try to start the engine .The cause of the engine back fire is ignition timing not in order.

Souds like ignition module has failed. Check for 12 volts to mod and replace mod if voltage is good.

Your likelihood that it was your coil in the first place was slim. First thing to check is your fuel pressure. Not enough fuel pressure, your ECM won't let your coil fire.

From karjunkie:

If the plugs get wet, then you have a spark problem somewhere in the ignition system. Pull a spark plug and hold it against a ground while you turn the engine over. You need to see a fat blue spark. If not, check the distributor, spark plug wires and coils. An easy way to test for spark is with an inexpensive spark tester. This is a device that is readily available at most auto supply stores. If the plugs do not fire properly, check the spark plug wires for fraying or cracking. Next, you need to check the coil(s). If firing voltage is low (weak spark), measure the coil primary and secondary resistance with an ohmmeter. If it is out of specifications, replace the coil. Also, make sure the coil is receiving normal voltage from the PCM or ignition module. If it is low, check the charging system for anything that may be reducing alternator output (battery and alternator cable connections, ground connections and voltage output).

check plugs wires for damage or just replace if you have replaced the #3 plug already if not replace it also

Subaru engines (including Legacy and engines of many other automobiles, GM, etc.) have returned to so-called wasted spark ignition systems since advent of the electronic distributor-less ignition (having been used historically in early engines with magneto ignitions). With this approach, the ignition systems are less expensive and usually quite reliable. At the same time, however, a shorted spark plug (cracked or carbon clogged, etc.) (or bad ignition spark plug wire) grounds both the ignition spark and the false spark being used. This means that it also grounds the corresponding respective ignition spark of the other 180 degree out of phase cylinder (that uses the same the same coil because the spark current is connected to the spark plugs of two cylinders). Since such a defect allows more current to flow in the spark coil to two plugs when the resistance of the spark plug gap disappears due to a cracked plug, etc, it seems likely to hasten coil burn out if the spark plug/plug wire defect is not corrected before installing the new spark coil.

To explain further, wasted spark means that when a cylinder is ready to fire, it gets a spark to its spark plug while part of the spark (from the same coil and current) as a sort of copy is also sent to another cyclinder at the same time but when the piston in that cylinder is exhausting its ignited gases 180 degrees out of phase from when its spark is needed. When the second cylinder is ready to fire and receives its "spark, the first cyclinder the also receivesa "wasted" spark "copy" of the one needed by the second cylinder. Economy is achieved in manufacture because otherwise electronics would have to turn on and off four different spark coils to distribute four different sparks as needed to the four cylinders. With wasted sparks (which are cheap), because the spark current of one coil is connected (internally in the ignition coil unit) to two cylinders that are in the same position but 180 degrees out of phase in firing, the system can turn on and off two spark coils twice as fast with half the electronics and fire two cylinders that are 180 degrees out of phase. A four cylinder engine thus uses only two coils, a six cylinder engine, three coils, etc., in a wasted spark system.