2001 F150 4X4 Supercab. Less than 50,000 miles. When it rains a lot outside, the moisture affects one of my coil packs. The truck will intermittently miss and buck and jump, mostly under a load. Seems to me I have a coil pack that is failing. Any trick to tell which one is bad? No codes are thrown out.

 

You will have to get it read professionally with a reader that provides live data. You could use Craigslist to see if someone has a Solus reader in your area. The live data will tell you which cylinder is misfiring.

However that is really really low millage. But the age of the coils and boots are probably the culprit.

 

Easy, drive it a few miles it'll throw a code, go to advance auto and have the code read it will tell you exactly which coil is bad. If you had a tuner with a code reader you could do it yourself, swapping the coil takes all of 5 minutes. MOTORCRAFT coil only! Use the code TRT30 online at advance and save yourself 7$ or so. I've had four coils go bad, I drove the truck in the 1500-2000 rpm range about 1-3 miles before the CEL came on, read the code with my super hip googled the CEL code, ordered a new coil and had the truck back in perfect shape within the hour. Driving it just a few miles with that miss isn't enough to foul the plug so no worries there.

 

Not necessarily, with his symptoms it would almost definitely pop a cel code. Only a slight misfire would take time to register.

 

lol okay.

 

You seem to have a problem with anyone who doesn't agree with your master mechanic teaching, I've replaced 4 coils all of which have thrown a CEL code. And age doesn't play as big of a factor as rain does with the design of the coils and they way they are positioned #4 tends to be the first to go due to water damage because of the fact that water pools in the back wells first.

 

Actually, it will have to perform many miss fire "hand shakes" with the computer before it will register as a permanent issue, which will will show as a fault and illuminate the "Check Engine" light. With his symptoms of only doing it once in a while, this will not be the case.

Unfortunately, Autozone and there brothers, usually only use a very basic code reader. That's why I suggest you use a live data handheld computer such as the Solus. this will show you all 8 ignition coils and you can determine which one is not performing as well as the others.

 

Did you learn that in your intro to auto tech class? The code (which will show up on a regular scanner as long as the CEL is illuminated will be in the range of PO30(1-8) PO305 meaning coil #5 (first coil on driver side bank has gone bad)

You're what we call a new guy who knows it all. Carry on bud.

 

Not all sir. In fact I have learned many things on this site that they never teach you in f.a.c.t. certification classes.

I specialize in electronics, ignition issues, and general computer issues as a career. I am merely trying to help the lad the correct way. I wouldn't tell my friend to drive his truck until the light came on. If he felt there was an issue, I would fix it correctly.

 

When your truck places best In show I'll consider your opinions. Otherwise I'll keep helping people with real life experiences and knowledge as I've had these problems before. He came here looking for the answer, I gave it to him. Also none of us care about your F.a.c.t certs and that's a FACT. A monkey can work on a 97-03 F150 with the right guidance. I suggest you move to the Honda Civic community that sounds more you're speed those guys seem to know everything!