No spark at coil - 1992 Ford Ranger

Look more closely at the 1 and 4 coil, also, check for trigger signal to these coils. I mostly suspect the trigger unit.

3.7L Engines
Each individual spark plug is located under each ignition coil. Each individual ignition coil must be removed to gain access to each spark plug. Refer to Ignition Coil Removal/Installation. Prior to removing spark plug, spray compressed air around base of ignition coil at cylinder head. This will help prevent foreign material from entering combustion chamber.

1. Remove spark plug from cylinder head using a quality socket with a rubber or foam insert.
2. Inspect spark plug condition.

To install:

1. Start the spark plug into the cylinder head by hand to avoid cross threading.
2. Before installing coil(s), check condition of coil o-ring and replace as necessary. To aid in coil installation, apply silicone to coil o-ring.
3. Tighten spark plugs to 27 Nm (20 ft. lbs.) torque.
4. Install ignition coil(s). Refer to Ignition Coil Removal/Installation.

I got code PO 305 on a 2002 Mercury Grand Marquis, what is the spark plug wire part called
This will have a direct coil over ignition with a coil over each spark plug. The coil is the electrical part over the spark plug. The coil also has a rubber part that is called the boot or spark plug boot. The boots can be purchased separately but the coils will come with new boots.

is it #5 coil,

Have you checked to see if there is any spark coming out of the number 5 coil?



and should I replace the coil and spark plug and what should the spark plug be gapped at?

When was the last time the spark plugs where changed? It may be due for all the spark plugs to be changed. The spark plug gap is usually listed on the emissions sticker under the hood. It should be .050 - .056 or very close to that.

REMOVE TOP ENGINE COVER,REMOVE CYLNDER HEAD CENTER COVER,YOUR WILL SEE IGNITION COILS SETS ON TOP OF SPARK PLUGS.ALL 4 SPARK PLUGS EACH, WILL HAVE A IGNITION COIL ON TOP OF THEM.REMOVE THE COIL SCREW THEN UNPLUG THE COIL ELECTRICAL CONNECTOR.REMOVE COIL, THEN YOU CAN REMOVE SPARK PLUG.YOU WILL NEED A LONG EXTENSION AND A LONG SPARK PLUG SOCKET TO REMOVE SPARK PLUG.

Hi,
REMOVAL
Always remove the ignition coil assembly by grasping at the spark plug boot, turning the assembly 1/2 turn and pulling straight back in a steady motion.

• Prior to removing the spark plug, spray compressed air around the coil area and spark plug.
• Remove electrical connector from ignition coil.

On 3.5L engines, it is necessary to loosen the screws by alternating back and forth. Do not lose the spacers under the coil when loosening the screws.

• Remove 2 fasteners from ignition coil.
• Remove ignition coil assembly.
• Remove the spark plug using a quality socket with a rubber or foam insert.
• Inspect the spark plug condition.

INSTALLATION
Always remove the ignition coil assembly by grasping at the spark plug boot, turning the assembly 1/2 turn and pulling straight back in a steady motion.

• To avoid cross threading, start the spark plug into the cylinder head by hand.
• 3.5L engines tighten spark plugs to 28 N·m (20 ft. lbs.) torque, 2.7L engine tighten spark plugs to 17.6 N·m (13 ft. lbs.).
• Install ignition coil assembly onto spark plug.
• Install coil screws and tighten: 2.7L engine to 6.2 N·m (55 in. lbs.), 3.5L engines to 6.7 N·m (60 in. lbs.).
• Connect the electrical connector.

I just did one the other day. There are three coils. You can determine which one is bad by using the number one spark plug wire and an old spark plug. Put the spark plug in the wire ( while it is still in the coil) and ground the plug against the engine block. Make sure it is grounded solidly to metal or you could get a nasty shock. Have someone start the engine. Look at the spark. It should be fat and blue. Turn the engine off as soon as you have seen the quality of the spark. Pull one of the wires from each coil in sequence and move the number one wire to that coil. Proceed as above. The weak coil(s) will have intermittent spark, yellow spark or maybe none at all. Once you know which coil(s) are bad remove the two small screws at the ends of the coil. They hold the coil down. Pick the coil straight up, pulling the contacts out of the ignition module. Set the new coil in place and screw it down. Both towers spark every time the coil fires so reinstall the wires in either spot on a given coil. Good Luck

The spark plugs are located below the 'coil pack' in a hollow tube in the head. You must remove the spark coil retaining screw to access the removal of the soark coil. The reoval with expose the spark plug at the bottom of the hollow tube in the head. The total spark coil is about 6-7" long and when it comes out that is when you will see the spark plug at the bottom of that tube. It sounds difficult to find but once you know it is easy. There is no coil wire(typical spark plug wire) attached to the spark coil. It is fed by a special connector on the side of the spark coil. Look on the side that has the least number of hoses and equipment in the way. Find the top of the spark coil (about 1-3/4-2" in dia) with a wire connected on the side. There is a single small metric bolt holding the spark coil in place. It will not come out until that screw is removed. I hope that this helps.

No spark to the coil or is it no spark from the coil? First verify that you have 12 volts to the coil when you turn ignition switch on if not you will never have spark from the coil going to the plugs. If you do have 12 volts to the coil and still no spark you have a bad coil. To see if the coil is firing, unplug a spark plug wire from it's plug and hold it to a chasis ground while attempting to start the vehicle. There should be a strong spark and popping sound. Remember to wear leather glove or thick work glove if holding the wire by hand to avoid shock. If there is a strong spark then coil is good.

If it's the four cyl., the first coil pack bolts over the #2 spark plug. The #2 coil pack wire plugs into #3 spark plug. The number two coil pack bolts directly over the number four spark plug, and the #2 coil pack wire plugs into the #4 plug. The firing order is 1-4-2-3.

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.