I've got an 01 F-150 with the 5.4, 4x4 offroad (if that matters). Anyhoo, I got a code last week for a cyl. 1 misfire along with some crappy crappy performace. There's a big shutter around 1500-2000 RPM under a slight load. it's constantly jolts at 70 when it's cruising at 2,000 rpm. SO I pulled the coil and checked it with the specs I found on here... 55 across the primary (across the terminals) and 5500 from either terminal to the end of the boot. Am I correct on my numbers and procedures? My meter is a goofy off-brand though, so I'm not totally sure about my results. It's digital, and the ohm scales are 200, 2k, 20k, 200k, and 2M. I checked the #1 coil first, then 2 and 3 just to be sure. I messed around and came up with 5800 on every coil across the secondary, but the primary would only register as a 1.1 or 1.2. Either way, all three were the same, so I didn't think twice about it.
SO I figured it was narrowed down to either a plug or an injector. So I went with the cheaper of the two and opted to put all new plugs in. The truck only has 55,000 miles so it probably didn't need it. WELL, I opted to buy the cheapest plugs, bosch platinums, and they sucked. i got misses like crazy and absolutely no power. So i researched and found i needed the motorcraft plugs. I got them, and everything was dandy. plenty of power, so so smooth, but THEN... then it got up to normal temp... that's when the trouble started. Same thing. There's no apparent miss at idle, so it's difficult to pull the coil power one at a time and listen. I had it in gear against a curb last night, with the parking brake on, and I would pull one and rev it while i stood infront. it was exciting except for a few times when i pushed too hard and it started to crawl up the curb at me. aaaaaanyhoo, ....
COULD IT BE... that the coils ARE alright UNTIL they get hot? then they expand or do something that causes a break internally? OR maybe an injector is funky? How do i check out my injeftors? I know I can get a hose and listen, but is there a better more accurate way? This is so irritating. I can change all 8 plugs in under 2 hours though, so that makes me happy. I saw that the time Mitchell allows is 2.6 hours. Go me. Anyhoo, I've spent a lot of time and more money than I intended on 2 sets of plugs plus grease and anti-sieze and a few wobbly extensions. Alright, enough blabbing. Ask away if you have any more questions. Thanks in advance!

 

I doubt the problem is a bad injector. I would bet money that it's a bad coil pack. Buy a new one from Autozone (about $50.00) and swap it out one-by-one with the original ones. After swapping, take the truck for a test drive. Eventually you'll find the bad one. Testing the resistance on the packs often will not tell you which one is bad. The other alternative is to take it to the dealer and pay the $80 for them to run the diagnostic in it. They can tell you exactly which one is bad. It's your choice. As for the Bosch plugs, you made a good choice by taking them out. They casued me some major issues.

Anthony

 

I paid an assload to have the codes pulled when the light first went off. They told me #1, and I assume they'd be honest. The original #1 coil is on either #1 or #2... I got them switched up, haha... I wanted to swap them and see if i'd get a code on 2, but I can't remember if I actually did swap them. I suppose I'll end up getting a coil. The light came on again today, so we'll see what the people can tell me. Hopefully I can catch the parts store and score a free reading today. Oh I hope this is all it is. I'm really starting to worry