I found my problem, you will not believe it, it was the sparkplug # 3. This is what happen I noticed this issue after a year of my Explorer being tune up it started to hesitate When cold, The first 30 seconds in the morning or with cold engine, This past July I went to Chicago for vacations I drove it is when it went very Bad , when On my way back to Detroit I put i bottle of STP injector cleaner, I did that every ½ tank until I took it to my Mechanic, he told me that wires were bad, I told him that they were a year old ( He change them), I agree for him to change them, but nothing, than he said are the spark plugs were bad, I told him the same just to get them out of the question, the problem still was misfiring 1 & 3, one of his guy told me that could be water in the gas tank I put an additive to take care of it , nothing, He gave up on me saying must be the Engine, Then I run 2 bottles of injector cleaner in an empty tank, nothing just improved a little bit, I say I need a Mechanic who knows Ford Engines, so I want few weeks after I did all the above he told me that the wires used were bad and not the silicone type, so he change the wires one more time, nothing still misfire 1 & 3 , I brought to him next day he told me that the spark plugs were removed and they looked ok, he put them back on but nothing, he said it was ok for a bit then the computer showed # 3 being misfiring, he said well, then is the coil pack, I change it my self, nothing, This guy gave up on me also, he told me he did not know what was the problem (An expert in Ford Engines), he told me to take it to the dealer because the have better computers, when some one do that to you your fears comes to hunt you big time thinking this is very bad and dealers are not in to the 50 -100 dollars jobs, I started my quest to solve the problem on my own I found so many issues related to this, of course trusting that the basic things were done by experts because spark plugs , cable change, coil pack being changed. I found that the Mass Air Flow Sensor need it to be clean if you have hesitation and or if your vehicle experienced lack of power, I check it, it was clean nothing, so I took another reading at Auto Zone the answer was right in my face # 3 . I ignore it and continue my quest for answers, I found the following items when your vehicle experience rough Idle or miss fire problems after you change the basic cable and spark plug job:
1.- Coil Pack could be bad. [ I change mine 98 bucks]
2.- Gas Filter Change [ 16.00 bucks I did replace it ]
3.- The gaskets need it to be replaced, [God knows how much is it to change them I did not replace them].
4.- Then the CO2 sensors need it to be replaced, [The CO2 $50 each my vehicle uses 2 I did not replace them ],
5.- The MAF has to be clean or replace it [cost around $135 bucks] I check it mine was clean
6.- Timing belt may be a possibility [this one was the scariest of curse I did not replace it]
The Solution:
I have friend he told me many horror spark plug stories where people are miss lead when plugs fail to spark correctly even when they are new, People puling their gas tanks out, gaskets changes, timing belts etc. he said you will laugh how minor in your case this issue is, I am sure are the spark plugs 1 & 3 just change them you will be OK. I doubt for a hile because my vehicle pass through hands of the experts twice in a short period of time. After I spend money for nothing I said OK I will give it a shot roll my sleeves and do it my self so I purchased 2 spark plugs thinking to ping point the problem, I am not a Mechanic by any means but I learn enough to find out the location 1 & 3, after some fears and a lots of how should I do this and is to tight toughts? finally I took # 1 out pushing hoses and deconecting few to make some way to reach it, When I took it out, it look normal wearing effects but the calibration was the same from out of the box which is 0.040 the recommended calibration for the spark plugs is 0.054 for my vehicle, I put a new one calibrated, then I proceed with # 3 it was a little better but still tight to get it out, I noticed that it was not as tight as # 1 when I took it out, I noticed gas build up and some grease around the thread, I would imagine it was a gas build up also, thanks God was not oil but just gas build up, I did the same procedure replacing it with a new one and calibrated to standards and making sure it was tight as # 1, I put few hoses back and after some minor cuts and burses, I started the engine and WALAAAAAAAAAAA, Engine light was off. Took it for a ride runs perfect no issue at by pass or lower RPM’s or cold, it is awesome, a feeling I being missing for a long time. I will change the other 4 plugs I did not change and make sure everything is well and calibrated with those bad boys.
The Cause:
Besides the going to those Mechanics which they did not do their diligent job to calibrate spark plugs, I contribute this issue to the spark Plug # 3 not being tight and not being calibrated correctly so may be the electrode at 0.040 it was arcing intead of sparking.
My recommendation Spark Plugs and Cables do it your self it is a little painful because is time consuming and the engine compartment is to tight to maneuver, Calibrate all the plugs to spec and make sure they are attached and tight to the engine (not very tight but tight, otherwise you will experience the rollercoaster I went through), when you do your cables buy the specific cables for your engine makes a big difference between 4.0L SOHC and OHV engines take one cable at the time, route and plug it as the old one ( very Important). Again start with the basics your self and make sure is dome correctly, you avoid many headaches.
I hope this helps to others experiencing this issue.
