I've looked up previous threads but couldn't find one that matches the ignition-issues I have with my truck.

My 2002 6.8L V10 runs very rough at low rpm's.

It's hard to detect while in city traffic, but it becomes evident on the open road.

I have replaced all coils with brand new genuine Motorcraft coils and all spark plugs (seemed to be the factory original) with Bosch Iridium Plugs.

No change...

The Ford dealership says, the truck needs a new PCM, which - according to them - has been discontinued.
I couldn't even find a PCM for my truck. All I find is the ECM which seems to be still available w/ California Emission. (it's a Cali truck, so that would be ok anyway)

Did anyone experience the same or a similar problem and it couldn't be solved by replacing all coils and plugs? And what was the solution?

The truck sits at the dealership right now and they're trying to locate a PCM. Any good hints are welcome...

 

What exactly are your "ignition issues" you list several things you have done to correct the problem but you haven't hold us what the symptoms are? codes are? performance lacking? Let us know and I'm sure the great people here can help you.

 

Sorry, the symptoms are:

Lack of power and shaking at low rpm's, misfire in several cylinders.

Error codes:

P0300
P0316
P0360

After deleting those codes, the MIL will stay off until the next start.
Then it will show P0360 first and a while later also P0300 and P0316.

Also when cold, after the initial startup the engine will idle rough for a minute or so. Then it seems to run ok.

The symptoms are most noticible, when I drive the truck on the freeway at low rpm's (under 2000rpm). The engine shakes quite a bit and has hardly any power.
Over 2500rpm it's not really noticible anymore.

All the COP's have been replaced with brand new, genuine Motorcraft COP's.
Some of the old COP's springs were rusty.
One COP had a broken bracket and was loose.
The Spark plugs have been replaced with Bosch Iridium plugs.
The old spark plugs appeared to be factory installed.
Some were wet and smelled like gasoline. One had a way a too small electrodes gap.

I hope this helps...

 

Did these lastet symptom's start after the new coils and plugs, or was that done to do resolve the issue but it did not? Why did you use Motorcraft for the Coils but not the Spark Plugs - just curious.

What the truck doing the same thing before the new coils and plugs?

 

I first noticed the symptoms after a trip to the Trona Pnnacles.

It was the first trip out of town with the truck and I didn't notice any shaking or lack of power prior to that (I've only driven it for a few miles). The road to the pinnacles is a bad washboard, approx. 5miles long. I drove slowly but it's impossible to avoid a certain amount of rattling.

Once back on asphalt, the shaking and lack of power became obvious. Also the Check Engine Light came on.
So I read out the codes and it showed the P0360 code (Cylinder J primary and secundary circuit)
I checked Cylinder J (10) and found that the COP was loose. The bracket was broken and the bolt missing. It didn't look like it had just happened.

Since it was Sunday I had to replace it with a cheap Duralast (Standard Motor Products - TruGrade) COP from AutoZone in Pahrump, NV.

There was no change and the symptoms remained.

So I decided to replace all COP's. I took the genuine MOtorcraft COP's. since I prefer genuine parts anyway.
I tool the Bosch Iridium plugs because they're better than the factory installed Autolite platinums (branded Motorcraft) and besides that, it's not necessary (actually iompossible) to adjust the gap on the Bosch plugs.

So to sum it up:

The symptoms occurred before the change of the COP's and plugs and did not improve at all after the change. The situation has not changed at all.

The Ford dealership ran a test before and after the change and they came up with the same results as well as the error codes still say the same (although I've deleted them after havin the COP's and plugs changed).

The Ford dealership says that the PCM is faulty and needs to be replaced. Challenge: The PCM has been discontinued. So there are apparently only used ones available, if any...
They're trying to find one through Ford's national parts locator or a reconditioned one.

Meanwhile I'm trying to find out, whether their diagnosis is correct, if somebody had the same problem and if so, what was the solution to solve it...

 

When is the last time you cleaned your MAF? Have you had the truck for long?

Might not help, but unhook your battery for a half hour and clean your MAF.

While you're at it (if you have time and it's relatively cheap) clean your TB, change your PCV and dump some seafoam into your gas tank... if you haven't had it for a long time or haven't kept up on maintenance, change your air filter and fuel filter... I mean if you've already thrown 10 new plugs and coils at it, what I'm mentioning is cheap...

I have a dealer near me that made me change my battery, the terminals and the starter relay when my truck wouldn't start... I told them to change the starter but they said it didn't seem to have moisture inside (?) even though ice was hanging from the casing and taping started the truck... I ended up changing the starter myself and haven't had a problem since... just saying don't think they're always right...

Your problems seem to be multiple cylinder misfire and a random misfire... check to make sure all connections are tight... if your plugs seemed fouled or smelled like gas, maybe you have a leaky injector(s)... I'm sure smarter people will chime in, but google the codes like I did and clean the necessary intake parts and change the cheap PCV before you dump to much $$ into it.

While you're at it, make sure your washboard roads didn't wiggle any vacuum lines loose.

 

If you have broken or loose connections at your coils you could also have the same at the electrical connections to your injectors, or bad injectors. Have you or the dealer checked the injection connectors to see they are all tight and none of the connections are broken?

 

i had something close to this happen after new plugs. ended up being 2 bad plugs. it really sucked doing it twice.


i find the idea of a PCM to be a far reach...but thats just my opinion.

 

You typically get the coil circuit malfunction codes if the harness is either unplugged or damaged at the specific coil. In your case J would be cyl #10. Was the old coil just loose or was it broken at the hold down bolt? If broken it may have been a plug ejection at some point in its history which may have damaged the wires. You are looking at the rear cylinder on the driver's side? I would recommend Motorcraft plugs since the Bosch plugs seem to have mixed results on our engines.

 

Don't use fancy plugs. Go what is proven to work which is the motorcraft plugs.
Cheap fix , do it first. Make sure to torque them correctly.

 

Rocknsoul not sure who these people are you may want to call them and see if they can be of any help if it is in fact it is your PCM
2000 Thru 2004 Ford Excursion

But I would do first what has been mentioned here by everyone first. When I first bought my X, on the 200 mile ride home I noticed that when I got into the mountains and the engine was under load I would get a misfire when on the gas. As soon as I took it out of OD the misfire went away, put it back into OD and would stumble again-asked here in the forum was told what to check. Did that problem gone-was worn out spark plug boots and no dielectric grease. Start with the easiest first

 

Up until now you've spent an awful lot of money through shotgun troubleshooting. Rather than any real diagnosis you threw the parts store at the problem, and the problem is still there. This is why I absolutely hate it when people on here recommend throwing a set of COPs at a problem whenever a truck isn't running right.

There are lots of things that can cause a misfire, so let's consider this for a minute. P0300 and P0316 are symptom codes; they just tell us that the computer senses a misfire, and it's not attributed to only one cylinder.

The P0360 means that it's detecting a fault for the coil driver on cylinder 10. Lots of things can cause this, and see below for the factory troubleshooting steps for this. Note that checking for a bad COP is the LAST step here.

 

And lastly, it's entirely possible that the dealer is right and it's a bad PCM.

 

Rocknsoul:
The Ford dealership says, the truck needs a new PCM, which - according to them - has been discontinued.
I couldn't even find a PCM for my truck. All I find is the ECM which seems to be still available w/ California Emission. (it's a Cali truck, so that would be ok anyway)

Here is a new PCM Varsityfordparts.com, gotta love the shipping charges.
2002 Ford Excursion ELECTRICAL Ignition system Pcm Parts
Never heard of them so I think I would call and talk to them first. But as has been said by everyone here try the trouble shooting first. Dealers will just throw in more parts, it's not thier wallet

 

Thanks for all the good tips!

Crazy001: The costs for new COP's and plugs were already in the budget. The truck didn't have any service records and unless I know the service history of a vehicle, I always get everything done immediately.
I had all fluids changed, cooling system flushed, transmission flushed and filter changed, both differential fluid renewed, oil change, etc.
Of course I was hoping that the COP's and plugs would already bring some improvement.
But no...

az_r2d1: The Bosch Iridium plugs aren't really that fancy. They have a finewire center electrode with an iridium tip. That's what you get from Autolite (Motorcraft) as well. The original plugs were platinum of course. But since the symptoms didn't change anyhow after putting in the Bosch plugs, I can pretty much rule them out as a reason.

tdappleman: Yes, it's Cylinder #10 (J) on the driver side. The hold down ring of the COP was broken off and the bolt was actually missing. It didn't look like that had just happened. Still, I didn't notice the symptoms prior to driving on that washboard dirtroad.

jayjjcc: I am not 100% convinced by the Ford dealership's diagnosis that it's the PCM. That's why I was asking for more and possibly different opinions.
I did not clean the MAF or Throttle Body yet. The PCV was on my list of parts to be renewed at the dealership. I assume the did what I was asking them to do. Since the truck is currently at the dealership, I didn't get to check for myself if it's been done yet.

The Air Filter is clean (it's a K&N ram air-intake though) and the Fuel Filter has been replaced recently (between my first trip and changing the COP's and plugs).

I did check the connectors to the COP's visually myself (looked ok and they all snap into place as they should) and had the dealership run a test, since I don't have the proper equipment.

Treker58: Thanks for the link! I will definitely get in touch with these people.

AlaskanEx: Yes, unfortunately that can happen easily. I'm checking each plug as good as possible before putting it in. But it's nearly impossible to see a fine crack in the insulator.