Help with F150 rough idle/hesitation/vibration

[JD4610]

Derek- The air bypass valves aren't coated, but if it's the kind with the vent cap on the side (round black plastic or plated steel) then Ford says you shouldn't spray solvent in those either. Supposedly it damages a seal inside that eventually leads to contamination and sticking. Again, there are people that clean them all the time without apparent ill effect.

As for checking it out with a scope, yes, it can be done. But to be honest I've never done it outside of the regional training center. On most vehicles, if I verify the miss I'll usually set WDS up for a power-balance display and brake torque the engine or road test to confirm the misfiring cylinder. Then I'll pull the coil on that cylinder and inspect it. Usually, and especially on the 4.6/5.4L engines, the miss is caused by arcing to ground across the plug boot. It's usually easy to see, it leaves a chalky gray line where it arcs.

As far as relocating, I am intrigued by the name of the area... /forums/images/graemlins/smile.gif

Stephen- RE my post to Derek above, if you were feeling especially energetic you could remove each of your coils and inspect them for signs of arcing. If you've never done this before it may take you a couple of hours and all you really need is a 7mm 1/4 drive socket and a couple of extensions (and a lot of patience.) Of course this would only identify an arcing coil, not one that is just weak. Wish you were closer, I'd love to help you out. /forums/images/graemlins/frown.gif

Jay

 

[bgott]

That truck ought to have some fusible links attached to the starter relay on the same stud the positive battery cable is attached to. Pull and yank and wiggle them and see if that causes the problem. If your parts house has a Beldon (sp?)electrical parts rack they usually have a roll of fusible link wire on it.

 

[hazmat]

Drove a couple hours yesterday - I got the hesitation/missfire once.

Maybe I'll pull the coils if I can find the time. My 1/4" socket extension collection is hurting - I've only got a 3" one. I had more, but they were stolen a few years back. My current tool collection stratagey is to buy it if I need it. /forums/images/graemlins/laugh.gif

Thanks again to everybody for their help & the coil spring help & the possesed dashboard help - got to love thread drift. /forums/images/graemlins/tongue.gif

If I don't get this fixed by winter, I'll have a darn good excuse to go skiing at Jay Peak. I'll have to come up a day early so Derek can fix my truck /forums/images/graemlins/laugh.gif.

 

[bgott]

Intermittent driveability problems are great fun! /forums/images/graemlins/frown.gifI'm sure glad I don't do that stuff for a living anymore! /forums/images/graemlins/laugh.gif

 

[BIGUN]

</font><font color="blue" class="small">( As you now know, the 5.4L engine uses a coil-on-plug ignition system, with individual coils for each cylinder. These coils have a reputation for failing, especially on cylinder number four, which is on the passenger side closest to the firewall. This would give you a miss symptom (vibration/chug-chug.) They aren't that hard to replace, but cost about $110 each for a newer updated design. )</font>

Let’s see, these engines have 8 coils at a cost of $110 each. $880 worth of coils with a reputation for failing, when for years we somehow got along with a single $30 coil that had a reputation for not failing. What progress, this must be one of Ford’s “Better Ideas”. /forums/images/graemlins/smirk.gif

 

[KENSFM]

</font><font color="blueclass=small">( What progress, this must be one of Ford's Better Ideas. /forums/images/graemlins/smirk.gif )</font>

In defense of Ford, they are not the only company to use such a dumb design. /forums/images/graemlins/blush.gif There is plenty of blame to go around.
Ken /forums/images/graemlins/smile.gif

 

[boustany]

Well, I replaced a bunch a coils, points, and caps in my time, none of which are present in my 4 runner (which is a 6 cyli nder and has 3 coils).

I think it the "reputation for failing" part which is the problem or, Ford's better idea. (Actually, I thought the new slogan was 'Quality is Job 1'? Maybe they gave up on that one to).

I'm sure I'll eventually run in to somebody with a Toyota who complains about the reliability of the engine. As it is, the 'car problem' a friend of mine has with his Camry is that its 10 years old and runs perfectly but he wants a new car.

 

[JD4610]

It's actually a good idea, just not perfectly executed. There's no maintenance to the system (cap, rotor, plug wires) and you get a much better spark (usually) with better water resistance.

And in Ford's defense, their updated replacement part has excellent reliability. In fact, I don't remember ever replacing one of the newer designs which went into production in 2003. But maybe it's just too early to tell. /forums/images/graemlins/tongue.gif

As far as the older cars having only one coil, that's fine. But what if that one coil fails? Then you go nowhere. On the newer vehicles, you can have a whole bunch of them go bad and the engine will keep running! It's a great technological advancement! Makes perfect sense, right? /forums/images/graemlins/grin.gif

Jay

 

[KiotiJohn]

</font><font color="blue" class="small">( I'm sure I'll eventually run in to somebody with a Toyota who complains about the reliability of the engine. As it is, the 'car problem' a friend of mine has with his Camry is that its 10 years old and runs perfectly but he wants a new car. )</font>
Yeah, I'm having a problem with my Toyota as it's been five years since I bought it new and I haven't once gotten the chance to go have something repaired. Haven't even replaced the battery. Now how can anyone have fun that way? John

 

[BIGUN]

Jay,

I know it sounds good in theory, but so many times it doesn’t work out that way. Another way of looking at it is you now have 8 times as many chances to have trouble with a coil. I have no idea how these coils are wired up but I would be willing to bet at some point they have a common component that makes them all fire, the computer or for sure the battery. When this common component fails all 8 coils will go dead.

I have owned and operated many single coil fired gasoline engines of various types for more years than I like to remember and I have yet to have my first coil failure. I was just guessing the cost of a coil ($30-Not from a dealer). /forums/images/graemlins/tongue.gif The thing that killed my ’84 Ford and my ’83 Toyota dead in their tracks were the little spark igniters on the distributor. Does the 8 coil version have one, eight, or none of these?

The point is I just don’t think the consumer is getting the $700-800 difference in cost worth of value in a system like this verses the cost and reliability of the previous electronically fired single coil systems.

Ford fans don’t think I am knocking Ford, I drive one myself but it has zero ignition coils. /forums/images/graemlins/cool.gif My wife’s Nissan probably has multiple coils too; luckily I haven’t had the need to know this. /forums/images/graemlins/grin.gif