A strange misfire

I just got a strange misfire today. I had a fouled plug with my original plugs and drove it hard and that disappeared. This is a recent set of platinums that were installed. I also had a set of Accel COPs put in at the same time. Maybe have 2000 miles on everything. It doesn't throw a code yet but you can feel and hear one cylinder isn't up to snuff. It doesn't show on the vacuum guage as anything burnt like a valve. It's rather a steady reading with the idle RPM not varying more than 10 rpm either side of 580. To me it feels like something on the verge of quitting functioning. Any ideas? 02 5.4L F-150

Could be your injector on that cylinder is going.

Brand new set of Accel injectors. Put in a few weeks ago.

Check your coil boot on that cyl. the boot might be allowing the spark to be shorting to the wall's...

Thanx. They're brand new but I'll give that a look see.

New ACC injector could be bad. Hangnig open and fouling the plug, OR not opening, OR it has debris from the assembly blocking the flow of fuel......

New/Bad get's past QC all the time....

If that's it I'm gonna be pizzed. I haven't gotten any DTC codes which confuses me.

I found the problem finally. It was #3 COP. I took resistance readings from the contact point spring for the spark plug to either of the input terminals. Accel is a reading of 6.3 on the 200k scale and compared to a stocker of 5.2-5.6. The third coil I replaced read 4.3 and I figured that was the culprit before I started the engine to try it. This reading confirms why it wasn't a complete misfire. I'm just still used to complete misfires from single coil setups. I'm not at all a chebie fan but the coil per cylinder setup is ez as far as troubleshooting. Thanx to all for the inputs.

Glad you got it! And I was kind of close with the booot thing

The bad COP left the boot on the spark plug when I pulled it out. About all I can see is there is a different amount of windings between stock and Accel. Boyit's fun hearing the tires again.