Hesitation under slight acceleration

[yammerslammer]

I was driving about 55mph up a very slight incline so I barely gave it a little more throttle and it started to hesitate/miss. I gave it about 25% more throttle and it straightened out and accelerated like normal. No check engine light. I kept playing around with it and the results are the same. Next, under full throttle the battery light starts flashing. I just replaced the battery last week. I wonder if a coil is going bad, or is it the alternator or something else electrical. Also, the fuel filter was replaced a few months back.
2003 4.6 w/91,000 miles

 

[Ron1978]

coil pac bad, it happed to my 2006
new coil and plug from ford was $325.00

 

[Soldier777]

if you can wait for shipping you can get it a lot cheaper on ebay

 

[Wint]

My 2000 does this at around 45mph, I had no idea how to explain it yet here we are. Is there any way to test this before I drop the cash on the coil? Also, from what I can tell by googling, I'm seeing "Coil Packs" which apparently are coils for each cylinder, is that what you are referring to here? Is it better to buy a pack of them (I found 8 for $126) or just somehow isolate which one is going bad?

 

[markanthony]

The best way to see what is really going on, is to take ur truck to dealer and spend the $60 to $150 for the to tell you which one is fouling up. Or just drop the cash to replace all of them with new plugs while your their.

Another thought is to get one coil pack and start with one and drive it. move on down the line moving that new one till it stops acting up...

these trucks have a total of eight (8) coil packs. One for each plug. I would just replace them all. I used accell coils on mine and have loved them. I spent like ~$300 for plugs and coils.

 

[Wint]

Thanks for the reply. Since I'm a new owner, I like to know where I stand before I take the thing in so I don't get talked into making fixes that may or may not work.

 

[markanthony]

Just as easier to replace all the plugs and coils then to dork around with stealerships or one at a time deal...
HEAR I would look at a quick look at my local parts store for what I replaced on mine..

 

[Wint]

I broke down and took it to the dealer, I just didn't have time. Sure enough one of the coils was bad, total repair cost including diagnostics etc was $250, which I can live with.