Appears when spark plugs were replaced; one of the plugs was not properly seated. one plug/coil assy broke off mount. removed both plug and coil. plug still attached to coil. first four threads looked stripped and the rest of the threads looked ok. hopefully just need to tap out hole. is their a way to re-tap with out removing head? if i have to remove head. should i be aware of or careful with removing something?

You don't say much about the problem, but here's a trick used for hard to get plugs.

Use a old plug wire plug boot to pull the plug out when it's loose and to re-install the plug. Many times you can get a plug loose but it's not easy to turn the tool, that's where the old wire boot comes in handy. push it on to the plug you can turn it more easy.

You have leaking spark plug grommet/seals under the valve cover, and most likely being a 91, also have leaking cam tower o-rings. The first is just a matter of replacing the valve cover gasket set. The second requires removal of the cam tower/rocker arm shaft assy. to access the o-ring seals between them and the head. If you are not an experience mechanic, I do not recommend doing this yourself. It is easy to damage parts and bend valves if you don't seat it properly.

Inspection

Inspect for the correct routing of the spark plug wires. Improper routing may cause cross-firing. Inspect each wire for any signs of cranks or splits in the wire. Inspect each plug wire boot for tearing, piercing, arcing, carbon tracking or a corroded terminal.
If there is any corrosion, carbon tracking or arcing indicated on a plug wire boot or terminal, both the plug wire and component it was connected to should be replaced.

Removal & Installation

3.5L Engine

1. Before servicing the vehicle, refer to the Precautions Section.
2. Remove the left side spark plug wires from the spark plugs.
3. Remove the left side plug wires from the retaining clips.
4. Rotate the engine for access as follows:
   1. Set the parking brake.
   2. Shift the transaxle into neutral.
   3. Remove the engine mount strut bolts. Swing the engine mount struts aside.
   4. Install the Engine Tilt Strap J-41131.
   5. Pull on the engine in order to rotate the engine forward.
   6. Tighten the strap.
   
   
5. Remove the right side spark plug wires from the spark plugs.
6. Remove the plug wires from the retaining clip.
7. Remove the spark wires from the ignition coils.
8. Remove the plug wire assembly from the engine.
   NOTE If you are replacing the spark plug wires, the spark plug wire conduit and retaining clips should be transferred to the replacement wires.
   

To install:

1. Install the right side plug wires to the ignition coils and then the spark plugs.
2. Install the spark plug wires to the retaining clip.
3. Rotate the engine back to the original position.
4. Install the left side spark plug wires to the ignition coils and then to the spark plugs.
5. Install the spark plug wires to the retaining clips.

3.9L Engine

1. Before servicing the vehicle, refer to the Precautions Section.
2. Remove the intake manifold cover.
3. Remove the left side spark plug wires as follows:
   1. Disconnect the left side spark plug wires from the spark plugs.
   2. Disconnect the left side spark plug wires from the ignition coil.
   3. Remove the left side spark plug wire clips from the intake manifold and heater inlet and outlet pipe.
   4. Remove the left side spark plug wire assembly.
   
   
4. If removing the right side spark plug wires, the engine must be rotated for access as follows:
   1. Set the parking brake.
   2. Shift the transaxle into neutral.
   3. Remove the engine mount strut bolts. Swing the engine mount struts aside.
   4. Install the Engine Tilt Strap J-41131.
   5. Pull on the engine in order to rotate the engine forward.
   6. Tighten the strap.
   
   
5. After rotating the engine, remove the right side spark plug wires as follows:
   1. Disconnect the right side spark plug wires from the spark plugs and ignition coil.
   
   
6. Remove the right side spark plug wire clip from the ignition coil bracket.
7. Remove the right side spark plug wire assembly.

To install:

1. Install the spark plug wire assembly.
2. Install the right side spark plug wire clip at the ignition coil bracket.
3. Connect the plug wires to the ignition coil and spark plugs.
4. If the engine was rotated for access, return the engine to the original position.
5. The remainder of the installation is the reverse order of removal.

Removal & Installation

3.0L (VIN S) Engine

1. Disconnect the negative battery cable.
2. Unplug the engine control sensor wiring connectors from the ignition coil and the radio ignition interference capacitor.
3. Tag and disconnect the spark plug wires from the coil by squeezing the locking tabs, then twist the tab and pull upwards.
4. Unfasten the four ignition coil retainers and remove the coil and the coil ground wire the radio ignition interference capacitor. Save the capacitor and coil ground wire for re-installation of the coil assembly.
5. Wipe the coil towers with a clean cloth dampened with soap and water. Remove any soap film and dry with compressed air. Inspect the coil for cracks, carbon tracking, dirt or damage and replace as necessary.
   
   

   Fig. Ignition coil assembly mounting-3.0L DOHC engines
   

To install:

1. Place the coil, capacitor and the coil ground wire onto its mounting location on the right hand valve cover.
2. Install the coil assembly retainers and tighten to 45-61 inch lbs. (5-7 Nm)..
3. Apply dielectric compound D7AZ-19A331-A or its equivalent to the spark plug wire boots.
4. Attach the spark plug wires to their proper terminals on the coil and make sure the boots are firmly seated so that the locking tabs engage.
5. Attach the engine control wiring connectors to the ignition coil and the radio ignition interference capacitor.
6. Connect the negative battery cable, start the vehicle and check for proper operation.

Hello sawjr.

From what you describe it appears you may have engine misfire.
Most common is a problem with an ignition coil that is mounted directly over the spark plug.
You also may be due for spark plug replacement.
Chances are your check engine light is on although sometimes it takes a while for it to come on.
Best thing to do is to have your system scanned for which cylinder is the one that is misfiring and replace the coil. Also may be a good idea to replace the spark plugs at the same time.
Spark plugs should be replaced on these engines by an experienced technician as they can break off on removal if procedure isn't done correctly.
I hope this leads you towards a proper repair.
Thank you for using FixYa.

KL

If there is a misfire, the cylinder that it is misfiring in will be recorded as a code in the computer.

Have the car scanned to determine which cylinder is bad. Then, replace the coil pack going to that cylinder.

Ignition Coil Pack Removal & Installation 2V Engine To Remove:

1. Twist the spark plug wires off of the ignition coil towers. Mark the spark plug wire positions so they can be installed in their original positions.
2. Disconnect the electrical connector from the ignition coil. CAUTION
   When removing the spark plug wires, a slight twisting motion will break the seal and ease removal.
   
   
   
3. Remove the mounting screws and remove the ignition coil.

To Install:

1. Position the ignition coil pack on engine.
2. Install mounting screws and torque to 53 in-lbs. (6 Nm).
   
   
3. Connect ignition coil pack electrical connector.
4. Match previously marked spark plug wires to ignition coil and install.

4V Engine To Remove:

1. Remove the RH cowl grille
   
2. Remove the screws and the water shield
3. Mark spark plug wire positions
4. Disconnect the spark plug wires from the ignition coil CAUTION
   When removing the spark plug wires a slight twisting motion will break the seal and ease removal.
   
5. Disconnect the ignition coil electrical connector
   
   
6. Remove the mounting screws and remove the ignition coil

To Install:

1. Position ignition coil pack. Install mounting screws and torque to 56 in-lbs. (6Nm)
   
   
   
2. Connect ignition coil pack electrical connector
3. Match previously marked spark plug wires to ignition coil and install
4. Position water shield and install screws
5. Install RH cowl panel

This is a fairly easy job. Do each cylinder one by one (removal and install), make sure to reinstall the coil on the same exact cylinder (DO NOT MIX UP). 1. Remove coil retaining scre 2. Pull upward on the coil to remove. 3. Remove spark plug (using a spark plug socket). 4. Properly gap new spark plug (if applicable). 5. Apply sprark plug anti-seize compound on plug threads. 6. Install plug. 7. Aplly coil boot grease on the coils' rubber boot tips. 8. Reinstall coil.

You shouldn't have to remove it....here are the steps from the tech manual:

Removal & Installation

1. Disconnect the negative battery cable.
   
2. Label and disconnect the spark plug wires from each of the coil pack towers.
   

Ignition coil removal—2.4L engine


Ignition coil removal—3.3L and 3.8L engines

1. Disengage the electrical connector from the ignition coil pack.
   
2. Remove the coil pack mounting fasteners.
   
3. Remove the coil pack from the vehicle. If equipped, remove the coil pack from the mounting bracket.
   

To install:

1. Place the coil pack into position on top of the engine valve cover, or mounting bracket, if equipped.
   
2. Install and tighten the coil pack mounting fasteners to 9 ft. lbs. (12 Nm).
   
3. Plug in the electrical connector to the ignition coil pack.
   
4. Connect each spark plug wire to each corresponding coil pack tower. The coil pack towers are numbered with the correct cylinder identification. Be sure that the spark plug wires snap firmly onto each coil tower.
   
5. Connect the negative battery cable.
   

you will have to replace the complete assy. the cheapest way is look for a complete wrecking yard seat, or have yours welded at a local machine shop

They are underneath the coils,there will be a coil,and under the coil will be a spark plug boot connecting the coil to the spark plug.