Why no fire on clynders 1,2,3?

Don't buy a new coil until you have tried switching one of the working coils with the no spark coil.Check the power to the coil with a "noid light".It will flash if a pulse is present to fire that coil.If no pulse then it's wiring or the computer.You can always cheat and grab "pulse" power "piggy backed" off an adjoining coil power for a quick fix..The engine won't care.

What is year--make--model and engine size?
How long since a tune-up? Are there any applicable trouble codes? With gasoline engine, if your saying no spark, have to check spark plug wires--spark plugs--ignition coil, primary voltage and ground for the ignition coil or coil pack.
Also, test with engine cranking, spark--proper fuel pressure and fuel injector pulse. If your missing all three have to check for rpm signal.

VALVE COVERS CAN LEAK INTO THE COIL WELLS AND SHORT OUT THE COIL. BUY A NEW COIL AND INSURE THAT THE PLUG IS GOOD AND NO OIL IS IN THE COIL WELL.

Lets see coil pack, spark plug wire, spark plug, and if it is MFI maybe injector, or check injector pulse. If all those are ok, then check the compression in that cylinder, if it is low it will not fire right. Go through normal check out procedures to check each of these pull out the spark plugs, put them back on the end of the wire and check for spark. If these are ok the go on go the injector. If they are not try temporarly swapping spark plug wires with a different coil pack, if the problem follows the wire, then put on new wires. If it does not follow the wire, then the coil pack could be bad, or the signal going to it. If the spark is ok check to see if you have injector pulse signal going to injector. If it is ok replace injector. Hope this helps you.

the 5th wire is the coil lead

Hope this helps. The ignition coil:

• changes low-voltage pulses from the PCM to high-voltage pulses.
• fires 2 spark plugs simultaneously.
• has 3 transformers.
  • One transformer fires the spark plugs for cylinders 1 and 5
  • One transformer fires the spark plugs for cylinders 2 and 6
  • One transformer fires the spark plugs for cylinders 3 and 4

Spark plug wires:

• carry high-voltage pulses from the ignition coil to the spark plugs.

The spark plugs:

• change high-voltage pulses to spark at the gap, which ignites the fuel and air mixture.

The firing order is 1-4-2-5-3-6.

If your getting no fire at the coil. that's why you're not getting fire to your plugs and therefore it won't start. Change out your coil. This should fix the problem.

It is either a faulty fuel injector for cylinder 29try swapping injectors); or the coil module that sends signals to the individual coils..it is mounted inside the air cleaner housing., black in color, rectangular with a harness entering one side and exiting the other..

it sounds like the coil pack is bad so go ahead and replace the pack. that should fix your problem

1. Note: Electronic Ignition engine timing is entirely controlled by the PCM. Electronic Ignition engine timing is NOT adjustable. Do not attempt to check base timing. You will receive false readings.
   

The CKP sensor is used to indicate crankshaft position and speed by sensing a missing tooth on a pulse wheel mounted to the crankshaft. The CMP sensor is used by the COP Integrated EI System to identify top dead center of compression of cylinder 1 to synchronize the firing of the individual coils.

1. The PCM uses the CKP signal to calculate a spark target and then fires the coil pack(s) to that target shown in Figure 51. The PCM uses the CMP sensor not shown in Figure 51 on COP Integrated EI Systems to identify top dead center of compression of cylinder 1 to synchronize the firing of the individual coils.

1. The coils and coil packs receive their signal from the PCM to fire at a calculated spark target. Each coil within the pack fires two spark plugs at the same time. The plugs are paired so that as one fires during the compression stroke the other fires during the exhaust stroke. The next time the coil is fired the situation is reversed. The COP system fires only one spark plug per coil and only on the compression stroke.
   
   The PCM acts as an electronic switch to ground in the coil primary circuit. When the switch is closed, battery positive voltage (B+) applied to the coil primary circuit builds a magnetic field around the primary coil. When the switch opens, the power is interrupted and the primary field collapses inducing the high voltage in the secondary coil windings and the spark plug is fired. A kickback voltage spike occurs when the primary field collapses. The PCM uses this voltage spike to generate an Ignition Diagnostic Monitor (IDM) signal. IDM communicates information by pulsewidth modulation in the PCM.

1. The PCM processes the CKP signal and uses it to drive the tachometer as the Clean Tach Out (CTO) signal.
   

2.5L V6

The ignition system consists of an ignition coil, spark plug wires and spark plugs.
The crankshaft position sensor signal is the basis for ignition timing calculations. The alternating voltage signal from the crankshaft position sensor is digitized by a pulse former within the powertrain control module. This digitized signal is then used to position the closing time of the primary circuit of the ignition coil.
Ignition timing is determined by the powertrain control module in response to engine operating conditions based on stored data tables or maps. Once ignition timing has been determined, the powertrain control module interrupts the current to the primary circuit of the ignition coil thus triggering the ignition spark which is supplied to the cylinders through the spark plug wires and spark plugs.
The ignition coils are triggered by the powertrain control module in pairs (cylinders 1 and 5, cylinders 4 and 3 and cylinders 2 and 6) sending one ignition spark to the firing cylinder and one ignition spark to the corresponding cylinder on the exhaust stroke. This ensures that any unburnt fuel residues remaining in the cylinder on the exhaust stroke are re - ignited to provide cleaner exhaust emissions.
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2.0L 4 cynder

The ignition system consists of an ignition coil, spark plug wires and spark plugs.
The crankshaft position sensor signal is the basis for ignition timing calculations. The alternating voltage signal from the crankshaft position sensor is digitized by the powertrain control module. This digitized signal is then used to position the closing time of the primary circuit of the ignition coil.
Ignition angle is determined by the powertrain control module in response to engine operating conditions. Once ignition angle has been determined, the powertrain control module interrupts the current to the primary circuit of the ignition coil thus triggering the ignition spark which is supplied to the cylinders through the spark plug wires and spark plugs.
The ignition coils are triggered by the powertrain control module in pairs (cylinders 1 and 4 and cylinders 3 and 2) sending one ignition spark to the firing cylinder and one ignition spark to the corresponding cylinder on the exhaust stroke. This make sures that any unburnt fuel residues remaining in the cylinder on the exhaust stroke are re - ignited to provide cleaner exhaust emissions.
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Integrated Electronic Ignition System The Integrated Electronic Ignition (EI) System consists of a crankshaft position (CKP) sensor, coil pack(s), connecting wiring, and PCM. The Coil On Plug (COP) Integrated EI System uses a separate coil for each spark plug and each coil is mounted directly onto the plug. The COP Integrated EI System eliminates the need for spark plug wires but does require input from the camshaft position (CMP) sensor.
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