Misfire number cylinder 9

SOURCE: 98 f150 cylinder 4 misfire(4.6)-

it mit be out of time try advance your disbutor

SOURCE: engine code p0307 cylinder #7 misfire

It could be carbon deposits on valve seats keeping valves from totally closing. You can try getting you a can of motorcraft PM3 top end engine cleaner and get engine up to operating temp then remove one of the small vacuum lines from the intake and draw the contents of the can slowly into the engine.After you have drawn in the contents shut engine off and let it soak for about 45 minutes then crank it back up and let it run until it clears. Now it will smoke like a forrest fire while you are doing this so don't be alarmed,just tell the neighbors you are spraying for mosqitos.This may cure the problem. If not you may be looking at a valve job.
This can be verified with a compression test if this is what is causing it.

SOURCE: cylinder 5 misfire

you need to replace all 8 coil packs.

SOURCE: Have a 2003 Taurus, 3.0 engine that has a misfire

did you check the injector pulse on that cylinder and it also could be the pcm , i had a taurus and a sable with good coils stop firing 2 cylinders and it was the pcm ,the code it gave was secondary coil but changed the pcm and it worked fine

Jeffrey Turcotte

• 8991 Answers
• Posted on May 20, 2011

SOURCE: i have a 2004 ford freestar 3.9 The engine light

Hi, the first step I recommend is to check for spark. You can do this by starting the car and then carefully pulling up the boot to the #1 ignition wire at the coil. If sparks are jumping inside the boot, you have spark and the ignition system is working.

1. Ignition: If there is no spark, shut of the engine and use an ohmmeter to check the impedance of the coil. Take the boot off, and connect your ohmmeter from the coil terminal to the engine ground. The resistance should be around 10-20 kohms. If not, replace the coil. If yes, the problem is the ignition module under the coil.

Now, assuming you have spark (which I believe you do, because the coil runs 2 cylinders, and you only have one cylinder that is misfiring), the problem will be a lack of compression or a bad injector (or possibly the injector wiring).

Note: I will provide repair steps once the troubleshooting is complete and the problem identified.
Also, if you do not have a multimeter, you can get one for $10-20 at radio shack or even Walmart. It will save you money overall--or maybe you have a friend that you could borrow a meter from.

2. Injector: The next easiest test to run is to see if the injector solenoid is clicking. You can do this by holding a long screwdriver to the injector and hold the other end of the screwdriver to your ear. With the engine running, you should hear the injector clicking. If not, you have a bad injector or a wiring problem. To determine whether the problem is the injector or the wiring, pull the connector off the injector and measure the AC voltage in the connector with the engine running. The voltage should be 1-2 volts or similar to that voltage of any other injector connector.
If the voltage is good, but the injector is not clicking, replace the injector.

3. Valves/compression: the last possible reason for a misfire is a lack of compression. The intake valve must open to accept a fuel/air charge, and both valves must be closed for the cylinder to fire. Sometimes an exhaust valve will burn and not hold compression. A blown head gasket can also cause this problem. The test we use to check the valves is a compression test. You can borrow or purchase a compression tester if you get to this point. Remove a few of the spark plugs including the cylinder that is misfiring. Screw the compression tester into the spark plug hole and crank the engine for a few revolutions. Record the pressure on the gauge, release the pressure, and go on to the next cylinder. If the pressure is much lower on any cylinder as compared to the highest cylinder, the cylinder head will have to be removed to correct the issue.

Please let me know the results of your troubleshooting and feel free to ask questions as you go.