I replaced spark plugs after 157,000 miles to increase fuel mileage. After I attached the EI coil/module/cover assembly to the engine, the car would not start. It acts like the plugs are not making contact with the EI coil/module/cover assembly but I installed the boots to the plugs first before attaching the cover assembly. Any suggestions?

Who told you that one ? Module ignition modulator 2003 Chevy Tahoe ! No such thing! Your best bet would be to take your vehicle to a qualified repair shop .
The electronic ignition (EI) system is responsible for producing and controlling a high energy secondary spark. This spark is used to ignite the compressed air/fuel mixture at precisely the correct time. This provides optimal performance, fuel economy, and control of exhaust emissions. This ignition system consists of a separate ignition coil connected to each spark plug by a short secondary wire. The driver modules within each coil assembly are commanded ON/OFF by the powertrain control module (PCM). The PCM primarily uses engine speed and position information from the crankshaft and camshaft position (CMP) sensors to control the sequence, dwell, and timing of the spark.

Hello: I had a like condition on my 2001 Saturn L200 2.2 (over 200,000 miles) I replaced the module that is located in the upper cover on the valve cover located on the driver side. Before replacing check the connection at the module and check the connections at the PCM. PCM located on the passenger side below the cover at the bottom of the windshield.

Check for spark. My guess would be the ignition module going out, but could also be the crank sensor. The module sits under the coils. Check all coils for spark. If any coil doesn't spark, you can try replacing just that coil, but the problem may still be the module underneath. If you have a meter, run a resistance check on each coil from the terminals to ground. If the same coil that doesn't fire aslo has a different resistance, replace that coil.
If you have a meter, check the AC voltage on each of the crank sensor wires shown as compared to ground or battery positive. If the AC voltages are different on the three wires, suspect the sensor is bad, but also check the tone ring on the pulley (Fig 2 below) for any damage.
Please see my tip at http://www.fixya.com/cars/r5821173-doesnt_car_start_gasoline_engines for how to check for spark. These are genericinstructions.
The 3.3L engine is the only one with the C 3 I system. REMOVAL and INSTALLATION C3I Module See Figure 1

1. Disconnect the negative battery cable.
2. Unplug the 14-way connector at the ignition module.

Fig. Fig. 1: Distributorless C 3 I coils and module system - 3.3L engine

1. Tag and disconnect the spark plug wires at the coil assembly.
2. Remove the nuts and washers securing the C 3 I module assembly to the bracket.
3. Remove the 6 bolts attaching the coil assemblies to the ignition module.

To install:

1. Install the coil assemblies to the ignition module and install the 6 attaching bolts.
2. Install the nuts and washers attaching the assembly to the bracket.
3. Connect the spark plug wires.
4. Engage the 14-way connector to the module.
5. Connect the negative battery cable, then reset the clock, radio and any other accessories.

Ignition Coil(s)

1. Disconnect the negative battery cable.
2. Tag and disconnect the spark plug wires.
3. Remove ignition coil attaching bolts, then the ignition coil from the module.

To install:

1. Install the coil(s) and attaching bolts.
2. Connect the spark plug wires.
3. Connect the negative battery cable, then reset the clock, radio and any other accessories.

Dual Crankshaft Sensor
See Figures 2, 3 and 4

1. Disconnect battery negative cable.
2. Remove serpentine belt from crankshaft pulley.
3. Raise and safely support the vehicle.
4. Remove right front tire and wheel assembly, then the inner access cover.
5. Remove crankshaft harmonic balancer retaining bolt and crankshaft harmonic balancer.

Fig. Fig. 2: Harmonic balancer with interrupter rings on C 3 I system

1. Unplug the electrical connector from the sensor and remove the crankshaft sensor from the vehicle.

To install:

1. Loosely install the crankshaft sensor on the pedestal.

Fig. Fig. 3: Dual crankshaft sensor - C 3 I system

1. Position the sensor with the pedestal attached on special tool J-37089.
2. Position the tool on the crankshaft.
3. Install the bolts to hold the pedestal to the block face. Tighten to 14-28 ft. lbs. (20-40 Nm).
4. Tighten the pedestal pinch bolt to 30-35 inch lbs. (3-4 Nm).
5. Remove special tool J-37089.
6. Place special tool J-37089 on the harmonic balancer and turn. If any vane of the harmonic balancer touches the tool, replace the balancer assembly.

A clearance of 0.025 inch is required on either side of the interrupter ring. Be certain to obtain the correct clearance. Failure to do so will damage the sensor. A misadjusted sensor of bent interrupter ring could cause rubbing of the sensor, resulting in potential driveability problems, such as rough idle, poor performance, or a no start condition.

1. Install the balancer on the crankshaft and install the crankshaft balancer bolt. Tighten to 200-239 ft. lbs. (270-325 Nm).
2. Install the inner fender shield.
3. Install the tire and wheel assembly. Tighten to 100 ft. lbs. (140 Nm).
4. Lower the vehicle.
5. Install the serpentine belt.
6. Connect the negative battery cable, then reset the clock, radio and any other accessories.

Fig. Fig. 4: Distributorless C 3 I positioning tool J-37089 for installing dual crankshaft sensor.system - 3.3L engine

FRONT AND BACK JUST FOLLOW THE WIRES THERE THICK AND BLACK AND THERE,S SIX OF THEM AND THATS WHERE YOUR SPARK PLUGS ARE

1989 Chevrolet Corsica 2.8 liter V-6 VIN "W"




1989 Chevrolet Corsica 2.0 liter L4 VIN "1"




GM Corsica/Beretta 1988-1996 Repair Guide
Ignition Coil - REMOVAL & INSTALLATION

1. Disconnect the negative battery cable.
2. Detach the 8 or 11-pin harness connector, as applicable, from the coil and module assembly.
3. Remove the ignition assembly-to-camshaft housing attaching bolts.
4. Carefully remove the ignition assembly from the engine.
   

If the spark plug boots present a problem coming off, it may be necessary to use a special removal tool, first twisting and pulling upward on the retainers.

1. Remove the ignition coil housing-to-cover bolts/screws.
2. Remove the cover from the coil housing.
3. Detach the ignition coil harness connectors from the coil pack assembly.
4. Carefully lift the coil pack out and remove the contacts and seals from the housing.

To install:

1. Install new coil seals into the coil housing.
2. Install the coil contacts to the coil housing and retain with petroleum jelly.
3. Place the coil pack into the housing and connect the harness connectors.
4. Assemble the cover to the coil housing and install the attaching bolts/screws. Tighten the attaching bolts/screws to 35 inch lbs. (4 Nm).
5. Install the spark plug boots and retainers on the ignition assembly housing secondary terminals.
   

If the boots and retainers are not in place on the housing secondary terminals prior to installing the ignition assembly, damage to the ignition system may result.

1. Position the ignition assembly to the engine while carefully aligning the boots to the spark plug terminals.
2. Coat the ignition assembly-to-camshaft housing attaching bolts with an approved lubricant and install them into the housing.
3. Tighten the attaching bolts to 16-19 ft. lbs. (22-26 Nm).
4. Attach the harness connector to the ignition coil module assembly.
5. Connect the negative battery cable.
6. Start the engine and check for proper operation and performance.

Hope this help to solve ypur problem (remember comment and rated this post).

Each ignition control module (ICM) has the following circuits:
An ignition 1 voltage circuit A chassis ground An ignition control circuit for each cylinder A low reference circuit
The PCM controls spark by pulsing the ignition control circuits to the ICM to trigger the coils and fire the spark plugs. The PCM and ICM are internally protected against shorts to power and ground on the ignition control circuits.

The spark plugs are connected to each coil by a short boot. The boot contains a spring that conducts the spark energy from the coil to the spark plug. The spark plugs are tipped with platinum for long wear and higher efficiency.


Ignition Control Module (ICM) Connectors



Fig. Ignition coil locations 2001-2004 4.8L, 5.3L, 6.0L Engines



Removal & Installation
2.2L (L61) Engine

1. Turn OFF the ignition.
2. Remove the accelerator cable from the bracket.
3. Remove the accelerator cable bracket bolt.
4. Remove the accelerator cable bracket.
5. Disconnect the ignition control module (ICM) harness connector.
6. Remove the ICM retaining screws.
7. Remove the ICM from the ignition coil housing.
   

To install:

1. Install the ignition control module in the ignition coil housing.
2. Install the ICM retaining screws. Tighten the retaining screws.
3. Connect the ICM harness connector.
4. Install the accelerator cable bracket.
5. Install the accelerator cable bracket bolt. Tighten the retaining screws.
6. Install the accelerator cable to the bracket.

2.2L (Ln2) Engine

1. Remove the air cleaner outlet from the air cleaner.
2. Remove the ICM electrical connectors (1) and spark plug wires (2).
3. Remove the ignition coils bolts (3).
4. Remove the ignition coils and ICM assembly.
5. Installation is the reverse of the removal procedure.
   

2.4L Engine

1. Disconnect the negative battery cable.
2. Remove the accelerator cable from the hold down clip.
3. Remove the cruise control cable, if applicable.
4. Remove the bolt from the fuel line retaining clip.
5. Disconnect the 11-pin harness connector for the ignition control module (ICM).
6. Remove the bolts from the ignition coil and the ICM assembly-to-camshaft housing.
7. Remove the ignition coil and ICM assembly from the engine.
8. Remove the screws that retain the housing to the cover.
9. Disconnect the coil harness connector from the ICM.
   CAUTION When removing the housing from the cover, make sure the ground strap stays in place.
   
10. Remove the housing from the cover.
11. Remove the screws that retain the ICM to the cover.
12. Remove the ICM from the cover.
    
    
    Fig. Removing the ICM from the camshaft cover
    

To install:

CAUTION DO NOT wipe grease from the module or coil if the same module is to be replaced. If a new module is to be installed, a package of silicone grease will be included with the module. Spread the grease on the metal face of the module and on the cover where the module seats. This grease is necessary for module cooling.

1. Install the ICM to the cover.
2. Install the screws that retain the ICM to the cover.
3. Install the ground strap, if necessary.
4. Connect the ignition coils connector to the ICM.
   CAUTION When installing the housing to the cover, make sure the ground strap stays in place.
5. Install the housing to the cover.
6. Install the screws that retain the housing to the cover.
7. Install the spark plug boots and the retainers to the housing, if necessary.
8. Install the ICM assembly to the engine while carefully aligning the spark boots to the spark plug terminals.
   CAUTION The ICM cover bolts must be installed using isolator washers with the rubber side facing down.
   
9. Install the bolts that retain the ICM assembly to the camshaft housing after coating the bolt threads with LOCTITE, or equivalent. Tighten the bolts to 16 ft. lbs. (22 Nm).
10. Connect the ICM 11 pin harness connector.
11. Install the bolt to the fuel line retainer clip.
12. Install the accelerator cable into the hold down clip.
13. Install the cruise control cable, if applicable. Connect the negative battery cable.

Hope this help (remember comment and rated this).

Hello Vance.
Not too likely a fuel injector problem.
The ignition system on thes engines were much more prone to bad coils and spark plug boots.
Remove the cover again and inspect carefully the rubber boot that go over the spark plugs for burn marks.
If they appear Ok do the same on the coil/module assembly.
I believe the boots are available separately from the coil/module.
When you buy the parts required also get some di-electric grease and apply a thin layer to the inner part of the boot at the spark plug end.
Hope your repair goes well.

What size engine have your behicle?

2.2L Engine

1. Remove the ignition coil housing.
   NOTE Remove any water and debris from the spark plug holes before spark plug removal with compressed air. Remove the spark plugs with a spark plug socket.
2. Inspect the spark plugs.

To install:

1. Gap the spark plug, using round wire type spark plug gap gauge. Adjust the spark plug gap to 0.045 in. (1.14mm).
   WARNING DO NOT coat the spark plugs with anti seize compound. Over torquing could occur and damage to the cylinder head threads may result.
   
2. Install the spark plugs with a spark plug socket. Tighten to 15 ft. lbs. (20 Nm).
3. Install the ignition coil housing.

2.4L Engine
The spark plugs on this engine are located under the ignition coil and module assembly. To gain access to the spark plugs, the coil and module assembly must be removed. On the 2.4L (VIN T) engines, the spark plugs are platinum and require replacement every 100,000 miles (160,900 km) or 60 months which ever comes first.

1. Disconnect the negative battery cable.
2. Remove the 4 bolts retaining the Electronic Ignition (EI) coil/module/cover assembly (depending upon vehicle application), then detach the electrical connector. Remove the assembly by pulling it straight up away from the engine.
   
   
   
   Fig. To remove the cover, unfasten the four bolts, then pull the assembly straight up from the engine
   
3. If the connector(s) sticks to the spark plug, use spark plug connector removing tool J-36011 or equivalent, and a twisting motion to detach the connector(s) from the plugs.
   
4. Clean any dirt away from the spark plug recess area.
5. Remove the spark plug using the proper size socket, extensions and universal joints, as necessary. Hold the socket or the extension close to the plug with your free hand, as this will help lessen the possibility of applying a shear force which might snap the plug in half.

To install:

1. Lubricate the threads lightly with an anti-seize compound, then start the four spark plugs by hand. Tighten the plugs to 14 ft. lbs. (19 Nm).
2. If removed, install any the plug boot connectors that may have stuck to a spark plug to the EI assembly.
   NOTE Check to make sure the spring terminal is inside the boot.
   
3. Install the EI coil/module/cover assembly to the engine, while carefully aligning the boots with the spark plug terminals, by pushing the assembly straight down.
4. Apply Loctite®thread locking compound, or equivalent to the cover bolts. Install the bolts and tighten to 16 ft. lbs. (22 Nm).
5. If removed, engage the ignition cover electrical connectors.
6. Connect the negative battery cable.

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

2002 Pontiac Grand Am 2.2L MFI DOHC 4cyl

The spark plugs on this engine are located under the ignition coil and module assembly. To gain access to the spark plugs, the coil and module assembly must be removed. On the 2.4L (VIN T) engines, the spark plugs are platinum and require replacement every 100,000 miles (160,900 km) or 60 months which ever comes first.



Fig. To remove the cover, unfasten the four bolts, then pull the assembly straight up from the engine

More details in autozone.com (free register).

Hope helped. Remember rated this help. Good luck.

2.2L Engine

1. Observe the following service precautions:
   
   Allow the engine to cool before removing the spark plugs. Attempting to remove spark plugs from a hot engine can cause the spark plugs to seize. This can damage the cylinder head threads. Clean the spark plug recess area before removing the spark plug. Failure to do so can result in engine damage due to dirt or foreign material entering the cylinder head, or in contamination of the cylinder head threads. Contaminated threads may prevent proper seating of the new spark plug. Use only the spark plugs specified for use in the vehicle. Do not install spark plugs that are either hotter or colder than those specified for the vehicle. Installing spark plugs of another type can severely damage the engine.
   
2. Turn the ignition OFF .
3. Disconnect the Electronic Ignition (EI) module harness connector.
4. Remove the spark plugs using a 5 / 8 inch spark plug socket.

To install:

WARNING Do not coat spark plug threads with anti-seize compound. If anti-seize compound is used and spark plugs are over-torqued, damage to the cylinder head threads may result.

1. Inspect the gap on the new spark plugs, re-gap the plugs as required. The spark plug gap specification is 42 inch. (1.0 mm).
2. Install the spark plugs and tighten to 15 ft. lbs. (20 Nm).
3. Apply dielectric compound to the spark plug boots and make sure no corrosion is present.
4. Install the ignition coil housing to cam cover and attachment bolts.
5. Tighten the ignition coil housing bolts to 89 inch. lbs. (10 Nm).
6. Connect the EI module harness connector. Push in until a click is heard and pull back to confirm a positive engagement.