There are generally only two things on a internal combustion engine which can lead to misfire, first is the lack of proper spark at the right time, and the second is a lack of proper air / fuel mixture in the cylinder at the right time. Obviously for the sake of argument, there are a lot of things others may be the cause of this failure of failures, but it is safe to say that these two problems are most frequent, and are both things that the average person can easily work on manageable with some confidence that they can solve the problem. It is always wise to start with simple things first, which are typically check if you have fuel and spark. how many spark plugs.
I called my friend to ask him what had happened on the Ford recently, and he said that the thermostat has been replaced recently. Therefore we thought that perhaps a stray coolant had leaked on the spark coils, which lie directly on the spark plugs, this is called a coil “on the sheet” design . Inspection in the coils I do not see anything wet, so I used the air gun to blow out the debris that may not want to fall into the cylinders after I removed the candles.
Next using a 7mm. socket and same sized wrench, I removed the coils from each of the spark plugs that had indicated a misfire on the code reader, and checked again that the area around them was dry. Next I removed the spark plugs to check for any signs that they were causing the misfire. The plugs on #7 and #8 looked a bit burnt, and had a light residue of oil on them. So after checking the coils with a voltmeter to be sure they were not burnt out, I went to the parts store and picked up 8 new platinum spark plugs that are specified for this 5.4liter V8 Ford engine.black spark plugs.
Before installing the new plugs it is always smart to check the gap, even though they are typically very close to the desired spec right out of the box. Using a feeler gauge you set them to the middle of your manufacturer specifications which can be found on a label under the hood. If you happen to own a Chiltons or Haynes service guide for your vehicle, it will also be in there, along with tips and tricks, plus torque specs. It is important to not over tighten spark plugs into the heads, since stripping them out is a really involved project to repair! The gap on these called for 0.052″ to 0.056″ so I aimed for 0.054″ as the ideal gap.
