Fast idle?

[bullet3z]

My 99 6cyl auto was not starting when it got cold. Now it starts just fine but I have hyper idle all the time. It idles around 1500 rpm's. It is killing my mpgs. I was looking through some old threads and there were a few post that say it might be the Idle Control Valve. How do I clean this thing out and what else should I look for? Also what is a good and safe way to clean the MAS?

[Midias]

I would check your throttle cable for binding and make sure the plate in your TB is closing fully by cleaning it out with throttlebody cleaner.

[Midias]

[bullet3z]

Just went to get the cleaners but I do not think that it is my MAS. I think it may be the fast idle sensor. The part is over $200 for a new one. I am going to try to locate and clean mine.

[Midias]

It is on the bottom of the throttlebody. I would completely remove the throttlebody from the and clean the entire thing with TB cleaner ad well as the IAC. Also I have learned from personal experience that cleaning the IAC with the tb on does little to nothing you really need to get it from the front and back.

[bullet3z]

Cool, that is what I was looking for. I just cleaned the throttle body, still on the motor and the MAS. This did not work. So I will have to take the throttle body off and try and get in there better. I would think that if that does not work then it is time to buy the whole unit and replace it.

Thanks for that photo, that was what I needed to see.

[Jakecallun20]

Real high idle? Before you go, changing expensive TB's and what not, check your plugs, wires, fuel filter, and regular tune up items. Alot of those cheap items can cause high idle. I had an idle of 2100 rpms ice cold and 1300 warmed up and I changed my wires, plugs, fuel filter, and then added a TRD air filter and my idle went down to 700ish when warm and about 1300 ice cold. Hope that helps.

[bullet3z]

I can say for sure that it is not the plugs and wires since those are less than a year old. I have had problems with this car since I got it. It had a hard time starting in the cold. Now it starts good in the cold but holds a high idle. The throttle body was dirty and needed cleaned out. But there was no crud in there that needed a screw driver to get it out. I will take it out and pull the high idle sensor off and clean that out too.

[System_Crash]

Quick question, do you hear a sort of hissing sound coming from anywhere on the engine? if so; you may have a vaccum leak somewhere

[bullet3z]

I have been checking to see if it is a vacuum leak because it does feel like it could be one. But I can not see any hoses that are disconnected or hear any leaks. Unless I am missing something.

[bullet3z]

I cleaned the throttle body from both sides. Removed the High Idle Control and cleaned the heck out of that. Put it all back together and still nothing.

UPDATE****************


Well everybody was wrong on this one. After over 1 year of either the high idle, not being able to start "fire" when it was cold and a few other issues. The problem has been tracked down.

We connected the vehicle to a Snap On Tools scan tool. Not one that just reads error codes since the check engine light was not on. After looking at all of the readings we were able to see that the engine coolant temperature sensor was reading a higher temp than what it was outside by over 20 degrees C. That in fahrenheit is way off. It would bounce up and down causing a spike in the idle. It would also not set the choke correctly for a cold start.

So, for a $30 part we replaced the Coolant Temperature Sensor and everything is working the way it should. Nothing like trying to track a problem down for almost 1 year. Then having a friend figure it out and fix it on the side of the road. The 2 shops that I took it to last year were not able to fix it. I had another thread about that last year.

[jxmac]

I was having a problem with high idling as well- startup was 2000+ and it took FOREVER for her to drop to around 800, if it did. I checked the plugs first, but they were fine. There was a little noise coming from beneath her, I figured there was a bit of an exhaust leak somewhere. When I jacked her up and took a really good look, I noticed my flex pipe was damaged. When I replaced it - tada, no more idling problems.

Just figured I'd post this fix on this thread too, in case someone else is having the same problem... give another direction to look at the problem!