Hey Joe.... I had the EXACT same symptoms going on with mine. I replaced the VSS and cleaned "all" my grounds. No change. I ended up finding 2 bad COP's.

 

Scott,

What points someone to COPS?

Joe.

 

@ X_HEMI_GUY Thanks for the pics and info. I did leave the battery disconnected overnight and it seemed to do fine for a few weeks and then went back to the ame stuff. I will keep all this in mind, after trying a few other things, I may replace it again since its such a cheap part. I have had many "new parts" in my lifetime that were bad and had to be replaced...
@TrdLtly, We dont have a big selection of Ford mechanics around here and the ones Ive been to have never done anything more than I can do but they charge me something outrageous so Ive not been pleased with the ones in my area. Ive seen many good ones across the U.S. just none here locally. We race Mustangs so Ive met many on the circuit just wish we had a good one around here. Im not a certified mechanic but Ive always done all my own work (except for transmissions, internal problems to them anyway). Now, I didn take this to another reliable mechanic in my area, not a Ford dealership and he came up with the same codes, ordered the output speed sensor from Ford but couldnt find where it went...he kept calling Ford back and wherever they were telling him it was, it wasnt.. (wife took it in so Im not sure where they were telling him it was). So of course, it still didnt get fixed. I have found a spot on the shaft but it doesnt look like the part they are showing for it would go there?? Thats why I was trying to verify where it goes and what it looks like if someone has a pic. I would rather do it myself then pay someone like that again. I paid 104.00 just for them to tell me they couldnt find it.. Now, I am going to buy a whole new set of 10 coil pacs and replace them too. Ive replaced a few here and there but never the whole set at once so I figure it couldnt hurt. Ive been reading online about people having these same problems and they all pretty much come back to the OSS and the coil packs. After reading, someone mentioned the A/C was causing the coil packs to cause the truck to die at lights, Ive had my wife turning the A/C off before stopping the past few days and have had no problem with it so I figure it has to be one of these 2 things. Ill replace the coil packs and the OSS if I can find out where it is and what it does look like.
I appreciate all the helpful info, I can do anything with a Fox Body Mustang, this X has been a different story but I am learning!!

 

Just to clarify.... I think the A/C that was referred in the other posts that you read should have been A.C. (Alternating Current) and NOT Air Conditioning. AC in a DC circuit is bad. It can cause all kinds of noise in digital circuits which will cause "gremlins" to appear. I work in the electronics world and have seen A/C cause even the best technician to stumble.

I "believe" that the coil windings in COP's are bleeding or shorting due to heat and/ or vibrations... or just poor workmanship. Either way the shorting/bleeding is causing the AC to be generated on the ground which in turn runs around until it dissipates. Because vehicles don't have "earth" grounds the AC plays havoc on DC circuits. There is a way to test for "Ripple Voltage" on a car, but I have found that unless you have an oscilloscope you will not get a very true result. Here is the pdf: http://www.pvv.org/~syljua/merc/TooSeptST07.pdf

Maybe an Electrical Engineer will chime in to clarify or correct me if needed.

The COP's I tried the first time were junk. eBay shipped from China with life time warranty.... if I want to ship them back to China. LOL They randomly failed at 5k miles similar to others on FTE. I did some searching and found another source for the COP's on eBay that were popular and had a good reputation with the F150's and Stang's. I called the seller (a business down in Florida) and talked with a real person in English. He was knowledgeable about the "other" COP's and said that they have had almost perfect results with their distributor. I am testing them now. We shall see.

 

The first thing that happened to me was the stalling on stops. Out of gear it had no issues. As soon as I put it in gear it would be fine for a couple of minutes and then the idle would drop to about 500 rpm's at which time it would just quit. If I drove with 2 feet and kept the idle up then I would have no problems. If I rolled up to the stop in neutral then I would have no problem. I cleaned everything (MAF, IAC, PCV, etc) and nothing changed. After a while of dealing with this I finally started getting the speedo-hop while driving around. For the most part, that is when I decided that it had to be something electrical. I had a couple of spare COP's that I swapped around and could get rid of the speedo-hop, but not the stall. I finally found the above mentioned COP's and installed those. Runs perfect now. Now codes. Mileage is back up where it should be. I don't want to recommend these ~$100 COP's just yet, but so far so good.

Scott

 

Good luck!

 

Didn't read everything but you're saying it wants to stall in reverse? Do you have any o2 sensor codes? My 4.6 (I know not same engine) would stall almost 1/5 times in reverse ended up being a bad upstream o2 sensor.

 

Im not sure where I read it but it was actually A/C. I googled this problem and it was one of the things I found. It was saying if you put the X under a load like towing or driving for awhile with the A/C on in really hot weather that it would cause it to happen so I thought I would give it a try and drove all day today and still no problems. Its just frustrating knowing there is still something going on and waiting for it to happen again.. it happens at the worst times like crossing into a bad intersection or something so I have to really watch for it until I get this figured out.
Do you know anything about the newer coil packs that are made with Copper? They cost more but reading the description, I thought it would be worth a try if Im going to go ahead and replace them all. Even if its throwing the transmission codes, I still think it could be the coil packs as well and like I said, Ive never replaced them all at once so even just for maintenance Im going to go ahead and do it.

 

No, just getting the transmission codes.

 

Ok, finally got my new coil packs in and installed. The X has been running great for the last 2 days with no problems at all. Hopefully this has fixed my problems! Ive had to drive it and these last few weeks it was miserable! Not sure what the A/C connection is to it (I wouldnt think it draws enough power but I guess it does) it got to where everytime I tried to take off from a stop with the A/C running it would die and keep dieing until it was turned off?? After taking off you could turn the A/C back on and it was fine unless you were going up a steep, long incline and then it would bog down some. It would even run when you stop, it was just as you take off it would die. Its been pretty hot here so its been a real pain to drive in stop and go traffic using the A/C. It never failed, If we forgot to turn it off, it would die. Also backing up a hill with the A/C would kill it. This has been the strangest thing Ive experienced!! I figured it wouldnt hurt to take some of your advice and get a whole new set of coil packs. I got a pack of 10 Motorcraft ones, copper wired, new off ebay for 139.99 free shipping!
No check engine light, codes or anything now! Thanks for the advice and I will keep you updated if I have anymore issues. Hopefully this will be useful to others with this problem!
Thanks!

 

Are you sure they are Motorcraft and not just clones? Thats a fantastic price if they are M/C ones. But doesn't really matter if it fixed your problem. I got the ones "TrdLtly" was talking about from FL, they are installed and seem to be working ok, only time will tell

 

They were advertised as Motorcraft so I hope they are, I never checked part numbers before installing. This company is out of NY, with a feedback score of 44694. The item number is: 400312077289

 

I don't believe that they are Motorcraft branded COP's. They relisted them here: Pack of Ten New Copper Wire Ignition Coils USA Made DG508 3W7Z12029AA FD503 | eBay

Just because they are probably not Motorcraft does not mean that you will have problems. The Chinese COP's are the ones that I would avoid as they are next to impossible to return if you do have problems. At least with this seller you have a toll free number you can call if you need to return them.

 

TrdLtly I belive that I purchased my coils from the same seller that you did out of FL. I have them on my X and seem to be doing fine, the only concern that I have is the resistance as measured with an Ohm meter, the Motorcrafts had a pin to pin of 0.8 and pin to spring of 5.45, the ones from FL had pin to pin of 0.8 but the pin to spring of 6.15(or close to) pin to pin is good at 7 or 8 but I have not seen the range for what is acceptable for pin to spring

 

Wish I knew exactly how accurate that testing is. In component electronics: a coil is a straight piece of wire, so to accurately test is nearly impossible. And COP to COP is not concrete. There is some range of what works and what doesn't work. I have several MC, Chinese and other COP's that I have tested. There is a range, but even ones that have caused problems measured in the window (ohms/resistance).

Here is a procedure that I found, but have not tried: Part 1 -How to Test 2-Wire Coil-on-Plug (COP) Coils.

I am just happy that if I have a problem with one of the COP's that I bought most recently that I have a company that I can call to exchange. My initial shipment only had 8 COP's. I called them and had it taken care of in just a few minutes.

5k mi was the limit on my Chinese ones. We shall see how the new ones do.