I have noticed over the last 5 or 6 months that I get a real intermittent stumble at 45 mph and again at about 60 mph. Went to the dealer (wrong move I know) and asked them about it. Did test drive (me driving) and could not reproduce. Believe it or not they did not do anything that cost$$$$. Said try to get it to throw a code.

Thus far I have not been able to get a code. Yesterday driving home from the farm (~100 miles away) and after abot 30 minutes of driving in ~90 degree weather on semi hilly terrain it really started jerking and bucking and acting really bad. Made it home and did not drive again until today.

This morning no prob. This afternoon no prob. Read a ton of threads here and saw a lot about COPs etc. Nothing matches exactly because it is hit or miss.

Any thoughts?

As an aside, I did have the tranny done as part of the natural course of maint just before it started. Recently had the fuel filter changed. Tried highter octaine gas. Could it be the ethanol or winter blendd we get in centeral VA?

Thanks (and sorry for the long post)

 

My 01 Supercrew is having the exact same problem. Just started a few days ago and only happens once in awhile around 45 mph. I just filled the pickup with fuel and wondering if there was some moisture in the fuel. I changed the fuel filter and add some isopropal to the gas tank and it happen twice to me today. Seemed to be more noticeable when I was bucking a wind. I have had no error codes. 75,000 miles on the pickup.

 

I'd still cast my vote for the COP's going. That's by far the most common culprit for misfires on the 5.4. And they don't "up-and-break" one day either, they slowly fade, giving occasional misfires at first, then it gets worse, and finally that cylinder dies altogether(which WILL toss a code).

The reason the CEL isn't on yet is because the PCU doesn't trip the light the instant a problem is detected. It gives itself a chance to correct the problem, and if the issue stops the light never comes on. Only if the PCU is unable to resolve the problem the light is tripped. Since you describe an intermittent off/on sputtering only at certain speeds, it may not last long enough to trip a code. You could try finding the speed it misfires at, and driving at that speed for several minutes(providing it won't cause a traffic issue). That may trip the light and thus, a code.

You can get all 8 COP's off a vendor on Ebay for like $100, which is a fabulous bargain, dealers charge you that much for one installed. And if you're going to replace them, replace them all. Don't just change the one that's spazzing out, if one is going, the others will follow shortly and you'll be in the same mess again.

My $0.02

 

I also have around 75 k. Started just around 68 or so k.

After reading many of the COPs posts I started to suspect that. Couple concerns:

1) Plugs -- have read that the heads have insufficient number of threads and that the plugs can stick. Definately don't want to blow a plug or strip the threads.

2) Cost -- I read that I can get them cheaper on the net (read it on the internet so it MUST be true!!!). How hard is it to get to the plugs -- I looked earlier and did not even see the plugs (must be under the valve cover between the header and the cover). I have done bottom up rebuilds on older vehicles. This engine compartment is way crowded. How do you get at the plugs (any instructional URL VERY appreciated).

I do not trust the dealerships (even though Richmond Ford thus far (as I far as I know)) has not done me wrong. Every time I have EVER brought any vehicle in for something major I have never gotten the same vehicle back.

Really appreciate the advice.

Thanks

 

Is there anyway of testing a COP to see which one is going bad when you do not receive an error code?

 

I read here that you should replace all of them just to be sure and to have consistenancy across all parts.

Make sense?

 

Yes , theres two ways. One way would be taking your vehicle to the dealership and have them "Mode 6" scan your cylinder history to see which one has been acting up.

Second way is a do-it-yourself type. You can purchase a COP probe from Carquest for about 80 bucks. The probe clamps to the COP and a built in light flashes with each pulse. To test during a drivecycle you must modify and extend the probe thru the firewall and have someone monitor the probe light as you drive. Do this 8 times if need be to find the weak COP.

Testing Primary and Secondary resistance as any manual provides instructions for isn't really applicable. If you have this type of failure your check engine light would definitely be illuminated and you could go get a free scan at any Auto Zone to reveal faulty COP. Unfortunatly COPs when weak start to fail under certain loads within the drivecycle. The most common misfire is about 45mph right after the truck shifts into overdrive.

Keeping your 8 part ignition systems integrity in tact is very beneficial with these motors. Therefore changing out all COPs at the same time has proved significant results in performance and economy. Many on this site have done this.

It's cheaper to just order 8 new ones from Global Automotive and replace them yourself all at once. There only $96 - That's for all 8 !!

http://cgi.ebay.com/ebaymotors/NEW-I...mZ160111254456

This link instructs you how -

https://www.f150online.com/forums/li...parkplugs.html

Good Luck

 

Are the COPs that Global-Automotive sells a quality product or should they be purchased from a Ford dealer?

 

Yes , better than Ford IMO - Ford doesn't offer a 1 warrenty on theres, Global does and many people here have purchased from Global . They have an A+ record. I purchased a few kits from Kevin (owner) last year for friends in the area and there still running great ..

 

Global automotive is a reputable dealer. I purchased 8 Cops for when I change out my plugs(5.4l 3V engine).If you change them out,heed the suggestions about using dielectric grease in the boots.
The plugs for the 5.4l 3 valve units are out of sight at the stealership.
There is a Ford parts supplier that has execellent pricing.