So out of nowhere my car is having an issue with the idle. It will idle normal(1000rpm) but then it will do this thing where the idle wont drop below 3000rpm. This just started last night and im not sure what to check. The car will idle normal then idle high then go back down to normal sometimes. What would cause this?

 

Also when its doing this and im driving the car will not go below 3000rpm even when i let off the gas completely. Its like cruise control being on all the time. I dont know what would cause this out of nowhere

 

Check for boost leaks yet? My bet is somewhere on the throttle body.

 

Im thinking maybe the sealant around the throttle body butterfly isnt sealing properly. It is a milspec 65mm throttle body

 

okay and heres why i cant figure this problem out...

i leave work tonight, start my car and rpms go to around 2,000rpm(normal on cold start) for a second and then go up to 3,000rpm again. so i drive not even a mile, and the idle goes to normal and the car is driving normal. car drove normal all the way from my work to my house which is about 10 miles.

i have no idea where to start looking for this problem at. and i have no idea why it just happens and fixes itself out of nowhere.

the car is on speed density so im not sure how a vaccum leak affects a car on SD. is it the same as a car running a MAF? im looking for any ideas on what to check since im completely stumped on this.

 

nobody has any idea what this can be?

 

Did your car have those issues before speed density? Have you called your tuner to see if there is anything funny in the map?

 

Talked to my tuner and he said if it was something in the map then it wouldnt of just started doing it out of nowhere. My car has been on speed density for months and had no issues at all. Like i said this problem just came out of nowhere and went away out of nowhere.

I drove to work today and the car ran normal. I am completely stumped on this

 

Did you get a chance to do a boost leak test? SD or not its still possible air can be getting past the idle screw or around the throttle body causing your rpm to go up.

 

i cant do a boost leak test until this weekend.

i just dont understand how this problem just went away out of nowhere. i would think a boost leak problem would not just disappear

 

I had this same exact problem for 8 months and i couldnt figure it out. Then i called STM and they told me to check a hose on my egr. The hose pops off and causes it to idle bad and the idle to drop. I reach under and it was off. i zip tied it on and my idle is fixed and my check engine light is now off. Hope this helps

 

i have no check engine light or anything to even go off of for starting to look for the problem.. it just wouldnt go under 3,000rpm out of nowhere

i guess this weekend i will go over all the vaccum lines

 

I had a prob a while back with one injector o-ring seal. Sometimes it misfired/caused idle issues and sometimes it didnt. It was a pain to track it down until a boost leak test.

Depends on the weather and how warm the car is. The rubber will expand or contract. Plus you mentioned that there was rtv around the throttle body. You could have a leak there. Good luck and keep us posted.

 

i went out and looked around the engine bay today and i cannot find anything that looks out of place or any vaccum lines that are not where they are supposed to be.

where is this EGR line i should check?

 

I was told By a guy i work with that this could of been caused by my IAC might have been sticking causing this problem. And now its unstuck which is why my car is acting normal now. Does this sound like it could be right?