dumb question but i'll ask anyway
 

I am new to Ford so here goes. I assume COPS are coils?? And how can you tell when they go bad?. What does a normal running Engine do when a coil goes bad and how do you tell which one it is?? :confused:

Ok 4 questions!

Coil over plug aka cop. They can intermittently misfire or just misfire. Most of the time it will set off a CEL but not always. If you have a misfire or CEL and suspect the coil. You can individually (while the vehicle is running) unplug each coil one at a time. When you find the one that DOESN'T change the way the truck is running (unplugging a good one will make the misfire worse), then that's probably it. Same goes for injectors under the same misfire conditions. If it is an intermittent misfire only under certain condition, say under heavy load or while accelerating that's usually a sign of a bad coil.

They unclip very easily with one hand. Otherwise it has to come off and be tested. But that is the easiest way.

Thanks Toyz!!:thumbsup:

Another nugget of info from this awesome forum!

Then let me ask a question. Wouldn't pulling the cop while its running lite you up? Sorry but I have been bitten before form other engines and I dont like it. Just trying to find out if the same thing happens with cops.

No it wont shock you. Its not like pulling a spark plug wire the coil builds up the charge. The high voltage comes through the boot.

And your not pulling the cop, your disconnecting the wire connector.

Got ya, sometimes I require a little more detail. Appreciate the info.

Just for your information....there are NO "dumb" questions if your not sure of something. There is a wealth of info here for everyone. Just have to ask.

I have a 2004 F150 and when accelerating and under engine load it struggles for power but cruises fine...I am pretty positive its a interm. misfire that being said can I test the coils the same way with my engine running and disconnect each coil? Also i cant get it to throw a code at all.

Most of the time intermittent misfires won't throw a code. You have the 5.4L? how many miles?

Yes and 156000

Sometimes, under load or heavy acceleration when its misfiring, if you try to keep it misfiring for long enough (long hill) you can get it to throw a code. Or, yes you can do the same type of test by unplugging the wire connectors to the cop's and injectors 1 at a time to try and pinpoint it. If you don't find it, I would suspect a bad plug if they havent been changed. If that's the case... I'm sure youve heard of the plug issues on your truck, you can decide what to do from there. Possible fuel filter if that hasnt been changed either.

Ive actually had all plugs changed at ford and replaced 4 of the 8 coils due to a nasty misfire from washing my engine like 8 months ago and water getting in the coils so im starting to think 1 or all of the other 4 r starting to go bad or something. Im gonna do some troubleshooting tomorrow and see.