Can a bad IAC valve cause my truck to idle so low it would turn off. If it does i have to replace the valve

 

Yes, it can. Lots of discussion on this with some cleaning it and others replacing it.

 

Cheaper to clean it, but better to buy a new one. And it's only a 20 minute job to replace it.

 

don't waist your time cleaning at best it just buys you some time.

 

I've replaced 4 IAC's in the last 3 years. I beginning to think that there is a circuit problem. Of the 4 changes (now on the 5th valve), Ford dealer replaced one of them because I couldn't believe that another one went bad in less than a year. As I suspected, it WAS bad, and according to the mechanic, it failed the pin test. All the others that I checked/replaced, also failed the pin test.

Usually, when one goes bad, snapping the gas pedal to the floor as soon as the engine fires, seems to make it work again. That gets old in a hurry.

Dave