Hey ya'll, replaced all the plugs (motorcraft) and COPs (globals) last weekend on my 01' w/ the 5.4L. Truck ran like new for a little over 200 miles, yesterday started hesitating & jerking w/ CEL flashing. Plugged machine to it and said it had misfire on cyl. #3. Read up on some other threads in here and believe it could possibly be a injector. Anyone had this problem? I'm thinking I need to swap #3 injector with another but not sure if there is a "specific" one to do it with. Also cyl. #3 is the third one back on the passenger side when your standing in front of the truck facing it right? Before I started replacing everything I blew off all the dirt around where the injectors go into the manifold and also blew out the holes after removing the COPs boots off of the plug. Could I have damaged a injector some how? Any help would be great, thanks guys

 

I would be inclined to think you either got a defective coil or you have a bad connection. Swap #3 with #1 coil first. if the miss moves its the coil..

 

X2 on the coil

 

Did you use plenty of dielectric grease?

 

Yea I put the grease on there but may not have put enough, I wasn't sure how much or how little to put on there...

 

Sounds like the coil to me as well. Do you recall if it was hard to get #3 coil to slide over the plug ? Those boots are so cheap they can kink withou enough grease on the insides.

Before bolting the bushing, you should have to put much down-pressure on the coil (if any) by hand. If you do, that might indicate a boot problem.

That happened to me on #4 once. - My fault. :o

 

While you're all talking about it...I've read about the 5.4s having a problem with stippd threads - guess there's not many threads to begin with - I've got 98,000 on my 01 and thought it's time to change them (although it runs great) - been waiting because of the horror stories I've read about replacing the head, etc. Anyone had such an experience - or is it such a low percentage? Thanks!!

 

I have had to repair this problem on two of my customers trucks. Both were 5.4s. They were 2000 and older. The plug blew out when they were going down the highway. I had to tap out the hole and install a heilcoil. They both were #3 cylinder. I haven't seen any newer trucks have this problem. Not saying that this won't happen. The one guy had it happen twice before he brought it to me to repair the problem. He just screwed the plug back in the first time and when on. When thos happens it brakes the cop off at the hold down. You can buy the reamer and tap for the problem. It takes about 2 hours to repair and a lot of skin.

 

Thanks - I'll be gentle changing and re-torquing the new plugs. If it happens on the road, I guess you would just unplug the injector and run on 7? Except for aftermarket add-ons, the only thing this truck has every gotten are brakes and fluids - it's been flawless. This forum gives a guy a lot of confidence about the truck - and knowing support is a click away - pretty cool! Thanks again.

 

It didn't seem any harder to get #3 cop on the plug than any of the others. But wouldn't it have been missing the whole time if it was just a kink in the boot? Like I said it did run great for about 200 miles. A mechanic here said to unplug each of the coils w/ it running, and when I don't hear a change in the motor then I will have found the problem. Will this work?

 

Usually not, not in my experience and I've messed with these ignitions quite a bit. First thing I would do is check to make sure the harness isn't contacting the AC accumulator (Top), The Mag Field can cause ignition instability. If so, tie the harness back w/zip tie and take her for a spin. Problem still there? Switch #3 w/#1 and reboot. She'll run okay at first (they all do ), but the misfire will move to #1 eventually if it is indeed a coil problem.

Before you re-install the coils, pull the boots and make sure the spring is fully connected to the coil blade.

If the problem stays @ #3 after moving, check out the injector and wiring harness.

The problem exist in one of the above. Most likely the coil - It happends from time to time.

Good Luck

 

Ok thanks for the help. I'm going to try it monday or tues when I get back. After I figure out the problem i'll let you know which one it was. Thanks again for all the great info.

 

The one thing I had my mind set on it not being, spark plug. Pulled it out and saw it was cracked, either from me putting it in or damaged during shipment. Either way, put another new motorcraft in and runs like hell again. Thanks for everyone who responded

 

It's running better now, yes? A hell of allot better

I cracked new plugs before changing them out on a 460. I was a PITA to. That engine was in a motor home. Not very fun to work on..