ok so ya know how when you start your truck it ildes high for a minute then goes down well now that i cleaned my TB and IAC valve it doesn't do that any more and i'm pissed cuase it will idle way to low when i start it up and it will make the voltage gauge flicker and the engine will ping
could the IAC be causing this a cleaned it three times over so its spotless and i used the right stuff



HELP???????????

 

Any check engine light? Are you sure everything is back together the right way and plugged in? The IAC valve will definitelty cause those problems, and if it ran fine before you touched it it's definitely something you messed up!

-Jon

 

No check engine light, an dyes everything is put back right this is really pissing me off

 

Have you got access to a volt ohm meter?

If so pull the plug and check resistance across the terminals. It should be 7-13 ohms. There is a diode in the valve so you may need to reverse the leads to get a reading. If the value is outside of 7-13 ohms then the valve is bad and it's time for a trip to the parts store!

Good luck.

 

Just tested and the ohm reading is 10.6

 

Sounds like the valve may be stuck in the closed position. The way they work on these engines is that they are open with the engine off.

On startup vacumm pulls them closed. The computer then opens the valve to bleed extra idle air into the engine during warmup.

Can you take off the valve again and blow through it? If not take a screw driver and work the piston a bit and see if you can free it up. If you can blow through it then I guess my theory is way off.

The only way to check output from the computer is with a scope. These are a PWM or Pulse Width Modulated idle air control valves so a VOM won't really tell you much as to what is going on there.

Hope this helps out.

 

You did reinstall the IAC facing the correct direction, didn't you?

 

well the valve is partially open when its off and i am sure its on right because it is only like this on warm up