After having a e-mail chat with GadgetmanTC in regard to cold temperatures and IAC modifications I went back to my Hyundai and wondered.. what if, since the IAC was external, I take a 1/8" ID tube and use it as a bypass for the IAC once the engine warms up.
Now, initially I had removed the IAC altogether and put in a plug with a 1/8" venturi for the idle air pathway, which worked fairly well but there were still some low idle issues. (did not keep it from getting some crazy gas mileage though. Had I stopped at the .5 gallons instead of the .683 gallons, the mpg would be more like 80mpg)
So, I put the IAC back into the system and attached a 1/8" ID hose from the plenum side to the manifold side. The idea behind this was the hope that the computer would use the IAC to warm up the engine, reach a point where it would want to idle down and because of the 1/8" line bypassing the IAC it would close the IAC off entirely to reduce the idle/air flow to a normal level.
The results I have seen so far is that the idle at cold startup is better, I can rev the engine and it will idle back down without almost stalling and otherwise the performance of the engine is good. I need to schedule a long trip for this vehicle anyway so I will be interested in seeing the results myself.
I would like to post a photo of the mod but not having much success at this point, I will put them on the Facebook page...
Karl Fortner
Tacoma, Wa.
Gadgetman Tacoma (Youtube)