I have a f250 with the 5.4 triton 2 valve engine. I just did new coils in it 4 weeks ago been running fine but recently its been running rough when cold but once it gets to operating temperature it seems to run better. New fuel pump, 8 new motorcraft plugs, 8 new motorcraft coils. Was wondering if possible injector problem? I grabbed my scanner got a cylinder one misfire. My assumption was possible faulty coil but when I tested the spark I got a nice bright blue spark. I pulled the spark plug out and it was soaked in gasoline. I was thinking at this point maybe a bad injector or stuck injector? Someone told me low compression but I would still assume it would ignite the fuel in the combustion chamber even with low compression. Is there any simples steps I could do to test this theory?

 

Is the place where the spark plug seats into the head clean? I mean really clean? That seat is the ground for the spark circuit. Also check if the top of the plug has a nub on it that screws in place or if it is fixed. If screw on be sure it is tightened with a pliers. A loose nub (forget the correct name) will give you a bad electrical connection and poor spark.
Regards,
Eric

 

I will check that as well if that doesn't work I was told to take the injector rail off and take a cup and turn the key on if the injector sprays while the key is on then the injector could possibly be stuck. Thanks!

 

Thanks y'all I finally figured it out. I have a camera from snap on that bends and twists. Did it very carefully too. While the engine was running I stuck it down the oil fill neck and watched. Cylinder one valves were not opening at all. I am a dummy for not noticing that on the compression test. I had a blonde moment I guess lol. But the hydraulic lifters failed. Thank god it didnt wipe the cam lobe out. But I put new lifters in and rockers made sure to bleed the new lifters too before I put them in. She pures like a kitten now. No more check engine lights. It runs really good for an old ford. Havent had any problems since. Its been fix for about 3 or so months now. I just forgot to post an update. The lifters and rollers weren't hard to install either. I rented the tool from my local dealership which allowed me to slip everything on without loosening the cam shaft. Kinda scary but it worked lol.

 

Thanks for the update !