VCT Sensors

I have a 2003 5.4 with a chronic misfire I can't get rid of.

I found out that the culprit could be the VCT Sensor but upon calling Ford, I'm advised that the VCT Sensors didn't hit the 5.4 until 2005.

I'm not sure if this is accurate though as I can lookup and find VCT sensors for a Ford>Expedition>5.4>EB

Can someone tell me if I do/don't have VCT sensors?

Ford is correct, VCT wasn't introduced until the 5.4 in 2005. The older ones had traditional fixed cam timing.

Could you describe the misfire more in detail? Is it always? On a specific cylinder or random?

Do a compression test on all cylinders to evaluate the misfire.

Skauber said:

Ford is correct, VCT wasn't introduced until the 5.4 in 2005. The older ones had traditional fixed cam timing.

Could you describe the misfire more in detail? Is it always? On a specific cylinder or random?

Click to expand...

It stutters at idle. It misfires random cylinders or can also throw specific to 3, 5 or 7. The CEL will go from solid on to flashing.
Also, it will suddenly clear up, run strong for about 50 miles then start back up from a slight stutter at idle.

The current codes are:
P0300
P0305
P0307

Run a tank of fuel system cleaner/seafoam.

Have you changed both the COPs and Plugs on cylinders 5 and 7? Also those cylinders are on the same head on the Driver's side. When was the last time you changed your fuel filter? Have you checked the fuel rail on that side for a clog or foreign matter?

ITWM, I would change COPs/Plugs 5 and 7 first. Change the fuel filter if its hasn't been changed lately. If you still have the problem after that, check the fuel rail on the Drivers side. No issues found, its probably an injector or burnt exhaust valve.

No smoking when working in the engine bay no matter what one is working on!
If changing any plugs, put on your safety goggles and use compressed air to make sure the plug recess and head is water free (water does not compress and will break a rod if any runs into an open spark plug hole).

I figured it out and you're not gonna believe it.

Back story:
A while back. The first thing that went bad was the EGR Solenoid. It burned up so I removed what needed removing to gain access to it and replaced.
Once done, I decided that the Triton 5.4L cover was only cosmetic and didn't actually need to be re-installed.

I found out the hard way that it does. Turns out that it is not merely cosmetic but also functional. It keeps water if any finds it's way under the hood from dripping down into the spark plug wells. All minus #5 which by looking at the picture is cut away to make room for the power steering reservoir. After another plug/COP replacement with LOTS of dielectric grease squeezed into each boot before install I have not had any further misfires. Granted that there has only been a few minor showers during the spring here in Texas and the real test will come this winter but so far so good.

Lesson learned. I will not leave this cover off again.

Transporter said:

Transporter...

Here is what I did to address any moisture in the spark plug well.

First, I cut strips of cloth and pushed them down into the wells to absorb as much moisture as possible.
Second, I MacGyver'd this contraption with scaled down sizes of tubing to connect to my shop vac to vacuum out the wells of any debris or moisture prior to plug removal.
Third, I bought a mini-endoscope camera to connect to my phone and look down inside the cylinder to ensure no debris or excess moisture remained.

Click to expand...

steelnewfie said:

Run a tank of fuel system cleaner/seafoam.

Click to expand...

After the COP/plug replacement, I ran a quart of straight acetone mixed in with the gas between two full tanks to clean/strip any carbon built up from the extended misfiring.

Glad you are running better. Hope its all cleared up. Almost all my COP issues have been due to water (Hurricane Ivan in Mobile, 11 inches of rain in two hours in Blue Ridge, driving in non-stop rain from New Orleans to Key West for example) but a few were over 90K miles so they probably were dying.

How much was the App Scope? Is there an iPhone model (although I do have a 7 inch Android tablet)? I have almost bought that little scope at Harbor Freight a couple of times but the 2.25 inch screen has held me back.