I had a vibration/miss that started at about 1800 rpms and up. No check engine light, no other indication of a problem. I would get up to that rpm, and the engine would start shaking like a cold Chihuahua, lol. In the back of my mind, I felt it was the coil packs, it seemed logical. I finally broke down and ordered them. All I can say is WOW. My 107k 4.6 just woke up, that's for sure. The throttle response is back, more power across the board. Even the exhaust sounds stronger, if you can believe that? I ordered from www.whitespitstop.com . They have them for $117.90 including shipping(to me anyway). If your 4.6 is feeling "doggy", give them a try!,,,,98

I'm in love with my truck again!

 

Thanks for posting 98SCREAMER.
My Jacobs ignition unit went south over the winter and with a supercharger project soon to be realized I was considering upgrading the ignition coils. That sounds like a fair price.

Also, while I am thinking about it I will warn anyone who is considering a Jacobs product or anything in the Mr. Gasket's large range of products. There is NO customer service. If you purchase you are on your own. I have been trying for 6 months just to contact anyone from Jacobs to try to get the ignition repaired (under warrantee) with no avail.

BE WARNED, STAY AWAY FROM JACOBS/MR. GASKET

 

what's the part number on that coil pack?

 

ACC140018 ,,,,98

 

Thanks.... lokks like my 99 has a different style. I'll have to do some checking to see what mine has. i'm not sure if mine is the 2 coil pack style or the 8 coil pack style.

mine has a slight hesitation, especially under load< AC, heavy accel > i am going to do a tune up this week. Plugs, wires, etc.

 

sounds like could be air filter, throttle body or MAF is dirty so clean those and u should get ur performance back.

 

Only earlier 4.6 engines had these style I'm pretty certain, and now all of them have COP ignition.,,,,98

 

Just order my set of coil packs for my 99 5.4L. Ordered them from Troyer Performance. $241.00 including overnight shipping.

 

I just got the Accel EDIS Coil Packs for my '97 F150 4.6L last month. I got 171k miles out of the originals. Other than getting rid of the random misfire problem, I got no performance increase whatsoever plus my gas mileage got worse. I put new plugs and wires in last year. I was kinda hoping for a little bit more pep, but didn't get it. Oh well. At least the problem at hand was resolved.

 

Hmmm, well I also have a few bolt on performance items. Possibly it was more noticable. Also, did you reset the computer after the install? Not that much of a boost to begin with, it could have came on so gradually you didn't notice?,,,,98

 

Yeah, I reset the computer. I've got about 400 miles on the new coil packs and I'll get on the loud pedal every so often and its the same as it's always been. I'm wondering if it's because I have Bosch Platinum 4's installed, instead of good ole Motorcraft plugs. They seem to be crappy plugs, from what I've read on this forum. I'm debating on getting some Motorcraft plugs and see if that makes the difference.

 

Could be possible. They're great plugs, but for these engines not so much. I hear from alot of guys that they may be the cause of a rough idle, misfires, etc. I even bought a set once, then started reading all the comments, and sold them. I have the plugs the dealer put in at 75k. I guess the Motorcraft platinum. I hear many good things about those other plugs, though. Not sure of the exact name.,,,,98

Neal could tell you, he's a big fan of them as well.

 

Finally I got around to putting in Motorcraft Platinum plugs since the truck was soooooo sluggish. OMG! That seemed to make the difference. The truck got it's power back and then some. I only had about 20k miles on the Bosch Platinum 4+s and they were trash. Some were burning too hot and some were burning too rich. Either way, the plugs were the fix!

 

Can someone please explain how a coil pack goes bad or becomes weak?

I changed plugs to copper cores and that made a big difference.
I had a set of motorcraft platinums in before (a month old), the coppers blew the plats away, on the seat o meter.

 

I installed Accell coil packs, Denso Iridium plugs, and Accell SuperStock plug wires at about 107k aswell (with a LOT of help from TexFord) and it really woke my 4.6 up aswell. I recently finally replaced the drive belt with a Gatorback, and with all of the above my truck is running aswell at 125k as it ever has. BTW, you can also get the coil packs from Mike Troyer.