My Ford F-150 has a misfire on the 6th cylinder.?

Question

Should a plug and wire fix it or could it be a coil-pack ?

Answer 1

I would try the plug and wire first that should fix it but if not then its in your coil pack but plug and wire should do it

Answer 2

well lets correct this first, a misfire or a fouled plug, or the term missing, or lost a cylinder , a V-8 has a 6th cylinder and well that not important now, but how do you know its the 6 th ? how many miles on the vehicle and a coil pack can give a missfire but they normaly don't go bad, but they do ,just just need to know the year of the vehicle, you could have a bernt valve that means the plug is firing but low or no compression ,in that cylinder ok,, you could not have it properly diagnosed and put a set of wires and a set of the correct spark plugs in it and its a good chanch this will fix it but it might not ,, you can pull that plug out or all the plugs and see if any are oil fouled and wich ones are not, and go from there, if no oil or gas fouled then its a compresion related problem ok, if your kind of handy with cars, and have a test light you can determan more with this tool by grounding out eack cylinder by poking it throug the plug boot and if the motor slows down or shakes worse that cylinder is good, when you find the one that makes no change thats the bad one, and you can also see if its the wire when you pull out the test light and hold it 1/8 to 1/4 inmches away it will arc to th test light, if it does not the turn off the motoor and pull that wire out of the coil pack, don't remove just unplug restart the vehicle and then use the test light again and see if it will arc to the end of the test light and the same distantace as you did at the other end of the wire, at the plug end and if it arc, its not the coil pack its a bad wire ok, have me so far ?, in this case I would get a set of wires and a set of spark plugs, and do your self a tune up, ok if the coil pack does not arc, then its bad ,and is the problem ok, good question, also if all this checks out you need to look elsewhere for it, mabey a fuel delivery syndrom and could be a bad fuel injector take care

Answer 3

You should be able to switch around coils, plugs, and wires. Try the plug, then the plug/wire, then plug/wire/coil. The misfire should switch to the other cylinder, and you'll have found it without buying any new parts. How are you diagnosing it, BTW? With a timing light? You can clamp the inductive pickup around the suspected wire and hold the trigger. You will clearly see the misfire as the light "skips." Also, does this truck have a distributor or distributorless ignition system? I was answering based on distributorless since you said "coil pack." Most coil failures I've seen were not low-speed misfires, though. You can also run the engine at night with the hood up and no lights shining. A bad wire will be evident as the spark arcs out in blue light. You can also mist some water on a suspected bad wire and it will start misfiring right away.

Answer 4

Sometimes it is just a one time deal, like you may have pumped some bad gas or something. Have the people at Auto Zone or any other auto part store reset your light. If the light comes back then we can be certain that the problem exists. In that case first, change the wires. It is a cheaper fix, if that didn't work you would have to change the coil pack. Change only the 6th wire and plug first to see if that solved the problem, if indeed that was the problem then change the rest of them..

Answer 5

what year some of the 5.7 3valve have bad injectors start with the plug and switch two coils and see if this fixes the problem if not see if is the same cyl. if it is then it is the inj. if not its the coil

Answer 6

did you do the simple fix first like reset the gap in the plug or switch wires to test the wire

Answer 7

give it a tune up change wires and plugs

Answer 8

odds are coil pack.
hope this helps and good luck!

Answer 9

Try the cheapest and then go up

Answer 10

either or, could be a bad fuel injector