I have a 2004 v6 3.8L mustang and the alternator, battery, spark plugs, and coil pack have all been replaced and when I press on the gas it bounces and does not want to really go? I have no idea what the problem could be and the service engine soon light is on and when scaned it says cylinder 3 misfire.

SOURCE: 1997 ford f150 cyliner 7 misfire

sme problem had to have it put on computer and codes reset

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: ford mustang - year 2000 - 3.8 liter. The coil pack is out?

I replaced the coil pack to no avail. I also purchase a code reader while at the auto parts store. This device told me cylinder 3 was misfiring (P0303). I found that the spark plug wire had shorted out on the manifold sensor tubes. Replaced that wire and done.

I highly recommend keeping a code reader in your car tool kit. very useful.

Bobby Memory

• 258 Answers
• Posted on Oct 23, 2009

SOURCE: Ignition coil pack on Ranger 1999 misfire on #3

replace coil