High Idle

Ok, it seems like all the preventive maintenance I try only seems to make things worse. this is my daily drive and all i have so I'm trying to take the best care of it I know how. when I start the truck it idles around 1500 with isn't bad when it's cold . after driving for 10 min the idle is around 2500rpm. if I kill it and let it set a min then start back up the idle is around 900 sometimes and other times 1500. the outside temp does not make a difference. I've replaced the air filter and found intake tube was cracked. I thought for sure that was the problem I replace the entire intake system with a cold air I bought off eBay but that did not fix the problem I have pulled the throttle body apart clean the IAC very well put it back together done everything I can think of I didn't notice if the AC vacuum valve broke so I plug the lines also the power steering vacuum hose broke so I'm plugged them as well I really just want to get this idle problem figured out!! throttle cable is not sticking , I've reset the sci. do not have a cel. I do have an air bag light on, cruise does not work but lights up like it does.

 

Have you tried disconnecting the throttle cable from the linkage and seeing where it would idle, just to completely rule out the cable and any possibility of it being tight?

 

I have come across a similar problem yet to be cured

 

I had the same problem about a month ago. I also removed and cleaned the IAC valve, and it didn't get any better. I bit the bullet and replaced the IAC valve ($129.00) and that fixed the problem. I also tried cleaning the maf, and everything else imaginable

 

I have not tried disconnecting the cable completely, but I will deff try it. the cold air intake I bought isn't a cold air at all but I needed the tube so I just bought the cheap one off Amazon for 50 bucks. I was changing the spark plugs and noticed there was oil around the threads of the number 4 cylinder so I'm going to have to replace valve cover gaskets as well as tube gaskets. is there any chance this could be causing High idle? I'm afraid you may be right elite Toyota it's prob the iac valve seeing how sometimes it works and sometimes it's higher than pterodactyl balls. I'm going to try and clean it again since I have to take it off to replace gaskets anyway. I wish I could find some sort of complete vacuum system diagram so I could trace it out but for whatever reason it's the only thing that is not available on the internet. I'm sure the kid I got the truck from prob tried some stupid cheap mod to get hp and I'm overlooking it. Hell it didn't even have a thermostat when I bought it. that should have been my red flag warning, guess I'll keep sinking what little cash I have into it till I fix it all.

 

Did you plug brake booster line to rule it out? unplug egr valve vacuum hose see if there is any change.

 

I got a cheapo blue tooth diagnostic tool and watch live charts to find my engine temp sensor was going from190 to 40. swapped the 15 doller sensor out and fixed the problem!!