well thanks guys for the input

Well I took my plugs from the dealer, and they are almost 20,000Klm old or a bit more( they are still not 1 year old )

about the wires: I don't know how old are they because I haven't changed them from the previous Owner along with the coils packs. <img src="/forums/images/graemlins/frown.gif" alt="" />

My truck has 192,000Klm on it( this is very Old)

How do I identify I bad butterfly valve?????
I did remove the air-hose to romove the ISC motor and I looked at the butterfly valve but I couldn't see anything wronge with at as far as I Know <img src="/forums/images/graemlins/confused.gif" alt="" />

I have tried to add A fuel Addictive(STP Fule injectors Cleaner)
and still didn't finishe the tank yet, but still with no improvments at all. <img src="/forums/images/graemlins/frown.gif" alt="" />

When I turn on my A/C it gets worse and the engine is like dancing( I could see it through the 4WD stick)

And if I rev it up the the engine it okay only past 3000-RPMs. so Only the low RPMs there is a problem