I have a 2007 4.2L V6 XL with 36,125 miles. I have been battling a jerking problem for a couple of months now. I first experienced knocking and jerking when accelerating only. Here is a list of things I have done using only Motorcraft parts and the outcome of each:

(1) I bought and used an Actron Auto Scanner--no codes found.
(2) I did a Chevron Techron fuel injection treatment--no change.
(3) I changed the fuel filter--jerking lessen a bit.
(4) I did a Seafoam treatment in gas tank and through the brake booster line and changed the spark plugs (insulators with yellowish appearance:"High Speed Glazing," according to the Haynes Repair Manual for Ford Pick-ups 2004-2012)--no more knocking.
(5) I changed the spark plug wires (Ohm measures on multimeter not bad but wear was present on some wires)--truck ran remarkably smoother but jerks under load or when going up hill.
(6) I bought an automotive stethoscope today and listened to the tapping fuel injectors--all sounded good.

What should I check or do now to stop the jerking when going up hill?

 

I came out of Publix one day and my truck had trouble starting and began to shake. I got a P0352 code. Only 4 of my 6 cylinders were operating. I took it to a mechanic who did a full electrical diagnosis and was told it was the PCM. My truck would not start after his diagnositic testing.

I had it towed to the dealership and was told I needed a coil driver and pcm. After almost 3 weeks of waiting for a pcm on back order, I get a bill for $1,703. I have my truck running right but my pockets are hurting