I searched but was unable to find solution so forgive me if this has been covered before.

1999 f-150 5.4 212k miles

Earlier this year I changed all COP's and plugs.
I am now getting misfire in cylinder 2. This problem has been intermittent and seems to be a little worse when the truck is cold. It happens at times after it has warmed up but isn't as bad or often.

I am planning on swapping the COP with #1 just to help isolate the problem. I am feeling as if it isn't the coil but I am going to anyhow, just in case.

What else could be causing the misfire and how do I troubleshoot the possible causes.

Thank you in advance,
Dave

 

It also acts a little "funny" when the problem is occurring. Like a slight lack of power and then it has power. Best I can describe it .... As if it might be a fuel issue similar to a lawn mower that is bogging down and then tilted back and allowed to clear out. Could this be a fuel delivery issue? How would I troubleshoot / fix?

 

I would definitely swap coils with #1 to see if code moves

 

Slight possibility the COP connector has lost its locking tab, will no longer seat and keep contact. If this is the case you could easily remove the wiring harness connector from the COP without even depressing that locking tab.

If this is the case---test before swapping the COP's----I use an NAPA #EC-259 replacement pigtail---about $20 each.

Another issue is what brand COP's were used? I foolishly changed my stock COP's out for Granatelli and within a year one-by-one they started to fail. It wasn't a complete failure rather after sitting overnight in 38* or lower outside temps there'd be a noticeable rough idle upon start up, CEL triggered. Once warmed up shutting engine off then immediately refiring temporarily cured the problem---until the next overnight scenario.

New doesn't always mean its not failed----some brands of COP's are known to be significantly lower in quality and longevity than the Motorcraft or similar brand.

Hope this helps!

 

I had the same problem with my f150, changed COPS and plugs, shortly there after had considerable trouble with #5, I removed the COP and found a badly fouled plug, replaced it and it has run great for the last several months.

 

If it is an intermittent problem I would definitely suspect the coil. Start there. If that does not fix it, then do the same with injectors, swap that injector with another one and see if the miss follows.
It could be a plug too. It is possible that the plug is not gapped right or is bad and when cold with a richer gas mixture it misfires. If you still have the problem after swapping the coil, then the injector, I would swap the plug.
I suspect you will find the coil to be your problem, just guessing.
First do what was suggested above and make sure your locking clip on the coil did not get broken. When the engine is cold, the wires will be cold and a little stiff causing them to push off the coil a little.
I can't think of anything else that will cause an intermittent misfire on a single cylinder.

 

I had the same issues for several months and on different cylinders. Fix it on number five, and a few weeks later number two would act up. Fix number two, and then number seven would have problems. And so on. Furthermore, even some of the COPs and plugs I replaced would need replacing again only a few months later.

It got to where I was keeping a spark plug and a COP in my toolbox and the toolbox on the floor behind the back seat. I think I can change the plugs and COPs in my sleep now.

It turned out that it was bad head gaskets which allowed coolant to seep into places it shouldn't go. Once those were replaced, the truck ran perfectly.

Your issue might stem from other causes, but it wouldn't hurt to consider the gaskets. (Especially if you're not familiar with the truck's history; I had purchased mine on Ebay and the seller was a little less than thorough concerning the truck's condition.)

 

definatly try switching coils

 

To clarify, the gaskets weren't the only issue. It was indeed fouled plugs. However, replacing the gaskets prevented the new plugs from getting fouled. In addition, I haven't had to replace any COPs, either.

 

Had same prob but cyl 3 spent mega dollars trying to fix turned out to be plugged cats.