As the series of the problems keeps on going:

Latly My 3.5 had been running very rough and vibratin around the low RPMs 1000-2500. And this is happening all the time even after the engine is in optimal tempreture.

It even gets wores as I trun On the A/C. I could feel the vibration through the 4WD Lever as it shakes.

My sparkplug have only 20,000Klm on them. And I use normal(not premium) Fule.

I have cleaned the Air Filter and I chekd the ISC motor(Stepper Motor) but I found nothing accourding to phsycal examineation(I found nothing wrong)

I hope it is not the betterfly Valve......

Any thoughts

Any help would be Appreciated