Misfire on one cylender that comes and goes new

It will have to be a spark problem,torque convertor don,t cause a miss in the motor ,check leads ,fit new plugs ,check gaps are 43 thou. Check coil or coil packs for cracks.

Cold starting misfires can often be caused by either tired high tension spark plug leads or ignition coil packs. If replacing leads, then replace with a full, new set. Coils can be changed individually, but it is often the case that if one has failed, then the others aren't far behind. Some cars have individual coil packs on each spark plug. Some cars have a single pack for all plugs and some have coil packs which may control two or more plugs.

To check for a misfire (ignition failure) follow these steps:

(Cold start) (Use a pair of insulated pliers)

1) Start the vehicle

2) When the vehicle starts misfiring, disconnect plug leads or coil pack connections one at a time. If the vehicle idles even more roughly, then that plug or pack should be considered fine.
Replug each connection before disconnecting the next one. Once you disconnect a plug lead or coil pack connection and find no difference in poor engine running, then you have likely found the offending cylinder. Check the spark plug condition, lead and/or coil condition and connections on that cylinder.

3) Replace components as necessary.

You might want to look for a vacuum leak on the intake manifold. You also might need to hook up a scope and measure injector duty cycle and compare it with a good cylinder. Also check wiring for chaffing going to the injectors and coil pack. I can provide you with pin out on ECM if you need.

I believe number eight is on the drivers side in the back. coil packs on these are easy to change outit takes an eight mm socket, one bolt. but befor you buy a new coil, try unplugging the connector and plugging it back in, corrosion on the leads can cause a misfire. also if you can use a ohm meter you can check the resistance of the coil. check between the two leads and the wire where the spark plug goes. reading should be around 5.6 ohm's

I HAD A 2004 FORD FUCUS THAT WAS DOING THE SAME THING I HAD A HARD TIME WITH IT
IT WAS THE COIL PACK IT STARTED GIVEING RANDOM MISFIRE CODES AND FINLEY NUMBER 4 CYLENDER QUIT FIRING AND THAT WAS THE ONLY REASON I WAS ABLE TO FIGURE OUT THE COIL PACK WAS GOING BAD THE HOLE TIME
I HOPE THIS IS SOME KIND OF HELP YOU CAN TAKE THE COIL PACK TO THE PARTS STORE AND HAVE IT CHECKED YOU CAN DO IT YOUR SELF WITH A VOLTS METER BUT I'M NOT SURE WHAT NUMBER IT IS SUPOSED TO PUT OUT GOOD LUCK!

P0304 Code - Cylinder #4 Misfire Technical Description Cylinder #4 Misfire Detected
What does that mean? A P0304 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #4.
FB.init("dd7d9e9681341cde77587bc6a2029f6f"); OBD-Codes.com on Facebook SymptomsSymptoms may include:

• the engine may be harder to start
• the engine may stumble / stumble, and/or hesitate
• other symptoms may also be present

Causes A code P0304 may mean that one or more of the following has happened:

• Faulty spark plug or wire
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter(s)
• Running out of fuel
• Poor compression
• Defective computer

Possible Solutions If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors
.

coil packs

Try to check the computer box and check if it is working and check the timing belt as well make sure it is properly tune up.

I’m happy to assist further over the phone at https://www.6ya.com/expert/ramy_d9e7ebea3891f482

You may consider tracing back from coil back to the main plug and checking wires going into and coming out of the plug for any broke wires make sure to look for collapsed casings sometimes the wires will break internally