So lets start this out with:

-I have fixed all the wiring to and from the OBD2 port
-my service engine soon light is not burnt out
-I changed all 8 plugs
-all coils are in spec... all within 1% of each other
-cleaned MAF
-verified all connections are set
-checked for vacuum leaks, couldnt find none\
-changed the fuel filter
-ran a big bottle of Lucas top end and injector cleaner thru it

AND I STILL HAVE A NASTY INTERMITTENT MISS! The truck isn't throwing any codes, or pending codes. I can still smell raw fuel dumping out the tail pipe, but 5 of my 8 plugs were bright white indicating a lean mixture, and the other 3 were tan. The tan ones were cylinders 2,5,7 all the others were snow white.

When it gets the least bit humid out it misses like hell. WHen I use bad gas it misses like hell. Under normal circumstances it only misses when throttle position changes, and after a few seconds it corrects itself and runs perfect.

Is there any way I can diagnose a faulty fuel injector or sensor? It almost seems like the truck is counteracting something then forgets it counteracts something and misses more.

The other huge challenge is the tach never moves when it misses. At idle it'll really miss like crazy every now and then~ but then other times within 2 or 3 minutes of it acting up it is fine.

The scanner from HP tuners wouldnt talk to the computer, if I can dig up a scanner is there somehing I should look for? This is driving me nuts

On the plus side, I'll post some cool pictures on an easy way I have found to service the SD's engine bay!

 

I've had a similar problem. I've got a 2003 F-150 7700 with the 5.4L and about 90,000 miles. I've had it to my mechanic and to the Ford Dealership about 8 times in the last year. Changed all plugs twice, replaced two injectors, replaced two coils, cleaned and then replaced the EGR, and a few other small parts and the usual series of diagnostic tests.

Anytime the weather is wet or cool, my 5.4 misses like crazy until it warms up to operating temperature. The "Service Engine Soon" light is then on for a week or two until it clears itself or I clear it with the code reader. The most common code indicates "Misfire" on one cylinder or another, most commonly #4. Nothing I do seems to fix it and no one seems to have the answer.

I'd be interested in hearing the solution for this problem.

My solution....I've got a 2011 Super Duty 6.2L on order.

 

Do you still have a catalytic converter?

 

Nope, it went by the wayside approximately 60K ago

 

If you're feeling generous you can order me one too

That'll solve my issues

 

This is a little offbeat but relevant, but this is the best way I have ever found to service the engine of my SD. I don't know how many of you have access to a chevy with a 9 inch lift and 37's but the bed height lines up exactly with the top of the grill... very comfortable to work on them like this









Made for changing the plugs an easy job, even #4 (the PITA of them all) came out relatively easily from this vantage point

 

If your ever in the Redford area let me know we'll hook it up to the computer and see what might be ailing it.

 

my buddy here in muskegon has a scan tool that you can use while driving and watch the operation of the o2 sensers and stuff call bloods 231 726 2838 see if they can get you a read

 

Even though your coils appear to be in specs, I wouldn't rule them out. I had a similar problem rotten egg smell, missing when throttle position is changed, missed when it was wet out etc. My truck wasn’t throwing any codes either. Turned out to be three bad coils. I replaced them and problem solved.


Recently, I noticed another misfire. Picked up a scanner with real-time readout. I drove to work with it connected and it reported a random misfire. Most of the time the misfire was reported for cylinder 2, but would appear occasionally on others. I replaced the coil on cylinder 2 and drove around with the scanner connected for a week. Problem solved.


It is not uncommon to get misfires when it is wet. If moister gets in, it can cause arcing between the coil and the cylinder head. New boots and silicone dielectric compound might help.

 

Its funny that a Chevy with 9" of lift and 37" tires is still shorter than your truck.

 

Well the last time I did the plugs I used plenty of dielectric grease and I did this time as well. All my boots actually looked brand new, they sealed up real well with the heads. Down in the plug wells actually looked brand new as well... unfortunately the rest of the motor is pretty dirt caked

 

Its a weak cop , happened to me and before and eventually failed on a very damp misty day.

 

Well I have one new COP chillin in my glovebox, is there a way I can isolate which COP is bad without playing musical coils or changing all of them?

 

You can try unplugging the electrical connector from the cops one at a time with the engine idling. Listen for ones that have little or no effect on engine sound and idle speed.

 

Oh thats all of them, I tried that yesterday... it idles perfect and smooth unless its humid, then its about every 20 seconds it misses once. If i ease into the throttle its fine as well, but when the throttle position abruptly changes it misses real bad for a few seconds then fixes itself