revs don't come back to idle
 

please help, anyone:

2006 bone stock 9 mr, 37kmiles. i accelerate normally in firts and second, and then brake (or coast), clutch in. the revs take FOR EVER to come back to idle. sometimes this is also apparent on downshift, such that the car fights the brakes.

no check engine light, gas pedal free, gas linkage lubricated (i was concerned it does not go back the the sheath), return spring on the throttle body works perfect, idle rock steady, no abnormal noises.

this started about two moth ago, and is intermittent.

thanks for any thougths on this,

peter:confused:

check your vacuum lines

ahhhh, vacuum lines, ahhhh, perhaos you can suggest a diagram or an old post? i looked but i am not sure i can tell what actually is vacuum....

pk

like how long does it take for the revs to come down

My IX does the same thing. When I gun it in first or second and push in the clutch and don't shift to the next gear, my RPM's come down slow. It is almost like I am in gear, engine braking, but i am not.

I talked to some one and they said it had to do with emissions. How? No idea.

What does you TPS voltage read when this occurs.


Log you car if you can...

Leaning towards vaccum leak.

well he is gonna need evoscan or something.............but vaccum leak does sound like the issue

Sounds like another case of throttle hang. Do a search on that and you will find many posts.

uninstall.

so this is what i got from the throttle float (hang):

1. BOV spring too stiff and
2. HOWEVER, this is just a partial cause, the Base Idle Speed Setting is a bypass valve, as is the Idle Stepper Control Valve, both let air past the throttlebody, and when you have a firmly springed valve, slight excess boost pressure, and a ICSV setting or BISS setting to increase idle speed to prevent some types of stalling, you will get the idle hang/raise..

i am still at a loss whys this happened after 2 years of owning the car, how to fix this, and how to diagnose this wihtout ambiguity so that i can stick the stealer with the cost of repairs.

i still cannot understand this: do we need to adjust the idle stepper table because there is no way to trick the clutch switch ? are there two clutch on/off switches or only one? why throttle hand is elimienated by the double triggering of the clutch switch???

thanks,

If it feels like it takes 4-5 seconds for the rev to come down in first after reving it to redline and putting the gear in neutral after that, then is just a normal thing for evos. A tune fix that lil' issue for me.

Your case sounds like it's happening on normal and high loads so the throttle is hanging for no reason. Yeah u better log the car and from there determine what is going on. Also check the vaccum lines and the throttle cables for sure.