No problem, I did NOT mean it that way.

SOMETIMES, it's catastrophic

 

I pulled the injector wire off so that it would not dump fuel into the cylinder that was not firing and then I just drove it.
It still pulled the trailer at 70 without an issue. Why would I pay to have it and my trailer towed when it runs just fine, other than a miss from one cylinder?

Neither a IAC or a COP will leave you on the side of the road.

 

Hey Art, call (641)774-2586 ask for Kelly, he is the head of their service dept.

It dam straight DID stop the vehicle and the ONLY thing wrong was 1 COP. The ECM detected to many miss fires and shut it down.

I couldn't figure out how or why either but I ended up picking Tracy up and lending him one of my vehicles for a couple days while they fixed it.

BTW, I will be interested in what he tells you cause if you get any other story then he lied to either you or Tracy.

 

Yes, it is sometimes. But gassers fail catastrophically too.....

 

That totally makes sense, what year was that truck? (probably newer than Art"s or Bill's....)

 

I would think running a dry cylinder would frig it up pretty good too.... esp if towing a load like that.

 

It's better than running a wet cylinder, the gas without spark would wash down the cylinder wall, get by the rings, and subsequently you would trash that cyl.

Running it dry shouldn't hurt anything, as the lubrication is done by the oil, and gas does not have any lubricating qualities to it.

 

Not an issue at all. When my 04' had the stock tuning it would go into open loop and turn off the fuel injectors during longer periods of engine braking, thus no fuel going into all 10 cylinders. Depending if I was pulling or not and how big the backside of the grade was I could drive miles with no fuel going into the cylinders. The pumping losses of the "dead" cylinders helped to slow the truck down. The rings/pistons/cylinder as well as the valvetrain is still getting a bath of oil the entire time. It was common for my coolant temps to drop after engine braking for a while. When you go back on the gas the engine comes back to life and your using fuel again.

 

No fuel going into a cylinder would be no different than an air compressor. As stated before, the piston gets all of it lubrication from the bottom side oil. Nothing from the fuel, be it gas or diesel.

 

The ECM will not shut down the entire engine because of one cylinder misfiring. It shuts off that injector and one next to it possibly, yes, but not the entire engine.

For misfire event monitoring for 2005:

"If a single cylinder is determined to be consistently misfiring in excess of the catalyst damage criteria, the fuel
injector to that cylinder will be shut off for 30 seconds to prevent catalyst damage. Up to two cylinders may be
disabled at the same time on 6 and 8 cylinder engines and one cylinder is disabled on 4 cylinder engines. This fuel
shut-off feature is used on all engines starting in the 2005 MY. After 30 seconds, the injector is re-enabled. If
misfire on that cylinder is again detected after 200 revs (about 5 to 10 seconds), the fuel injector will be shut off
again and the process will repeat until the misfire is no longer present. Note that ignition coil primary circuit failures
(see CCM section) will trigger the same type of fuel injector disablement."

http://www.motorcraftservice.com/vdi...f/OBDSM508.pdf

Further, on ignition coil monitoring:

"If an ignition coil primary circuit failure is detected for a single cylinder or coil pair, the fuel injector to that cylinder or
cylinder pair will be shut off for 30 seconds to prevent catalyst damage. Up to two cylinders may be disabled at the
same time on 6 and 8 cylinder engines and one cylinder is disabled on 4 cylinder engines. After 30 seconds, the
injector is re-enabled. If an ignition coil primary circuit failure is again detected, (about 0.10 seconds), the fuel
injector will be shut off again and the process will repeat until the fault is no longer present. Note that engine misfire
can trigger the same type of fuel injector disablement.
"

Now, I'm the first to admit that in-the-field observations sometimes do not follow what "the book" says. And a COP that is shorted could potentially cause the PCM to go into fits. But I suspect there was a fuse blown or some other cause that was not mentioned in idle conversation.

But this is the first time in 9 years of studying Ford's gassers that I have heard of one COP shutting down an entire engine. And by design, it doesn't happen on purpose.

 

Art I noticed that he said the ECM detected to many miss fires. Now I'm wondering if there is more going on then the 1 COP. I've been thinking about why 1 COP look like more than 1 miss fire unless it is a fuse. I've read and reread what you wrote. Your post stopped but what if the injector kept coming back on and the miss was still there. Let's say a dead cop or foaled sparkplug. Is there a certain number of trys before it needs that cycle. It sucks but it has happened, they coulda sold him a fuse.

 

IF this had been a different shop I could go along with them selling stuff they didn't need to. And I know you guys don't know this shop but it's a ford dealer in a town of 4000 people so everyone knows everyone else.

Also they didn't "sell" him anything, it was under warranty.

I read what the book says Art, but I have heard from other people of being shut down from a COP failure and witnessed this one first hand. NOT saying I have heard it as being a big issue or a massive problem like say 305 Chev engines cracking blocks or the supposed massive amounts of CPS failures on 7.3s (I mean we all know that the 7.3 was just going to leave you stranded from all the massive amounts of htose that failed) But this was not the first one I have ever heard of and it was from other shops, some private some dealerships.

 

It's an 05 F150 5.4

 

By no means am I suggesting that anything was sold. Even though I can't find a reason why a misfire would shut the engine down. And that might be the problem. We all know the engine will keep running with a foaled sparkplug or a dead COP. But can a COP create a condiction that the pcm thinks it needs to pull the plug? Just the fact you stated that the pcm detected more than 1 miss fire leads me to believe there is more going on than 1 dead COP.

 

They replaced 1 COP and the truck has been running fine for the past 3 months.


The tow truck driver who I also know fairly well told him this isn't the first one he had to tow in with that problem. take it for what it's worth.