Motor reving

[the_game_rock]

I have a 5 speed and whenever I take it out of gear it will sometimes rev to around 1500 and only go down when I stop or put it in gear. anyone know why??

[fasstdak]

Check for vacuum leaks (especially near the PCV valve) and when is the last time you cleaned out your throttle body?

[the_game_rock]

Originally Posted by fasstdak

Check for vacuum leaks (especially near the PCV valve) and when is the last time you cleaned out your throttle body?

alright ill check I havent cleaned out my throttle body. what did you clean it with?

[fasstdak]

You can use your favorite carb/tb cleaner (Berrymans B12 cleaner is what I use at home - BG at work). The best way is to remove the throttle body, remove the IAC Solenoid, and clean both the ports and bore of the throttle body - and the IAC plunger (make sure you do NOT twist the plunger...just spray it down and wipe gently). The IAC (Idle Air Control Solenoid - sometimes referred to as the AIS) controls your idle and will get clogged with carbon build-up over time. It should be serviced/cleaned every 25-30K miles.

[sheetmagnet]

Originally Posted by the_game_rock

I have a 5 speed and whenever I take it out of gear it will sometimes rev to around 1500 and only go down when I stop or put it in gear. anyone know why??

Um... 1500 rpm-down-to-idle after you stop could also be slight miscommunication between your VSS and your ECU program... which can happen frequently, and is quite normal to happen for periods of up to 5 seconds (in certain situations during periodic braking after driving in gear, your ECU anticipates you to upshift or downshift, and will add extra fuel in anticipation for you to re-open the throttle body and engage the clutch to efficiently transfer into a higher RPM range). Spark timing and fuel curve are also modified in those cercumstances. Unless your syptoms are relatively extreme and random, don't worry too much.

[fasstdak]

This is true...but also goes into more than the basic checks. The idle will stay above 1200rpm +/-100 until you're at a complete stop but that's regardless of being in gear or not. A dirty IAC can exaggerate this common function of the PCM and VSS.

[the_game_rock]

Originally Posted by sheetmagnet

Um... 1500 rpm-down-to-idle after you stop could also be slight miscommunication between your VSS and your ECU program... which can happen frequently, and is quite normal to happen for periods of up to 5 seconds (in certain situations during periodic braking after driving in gear, your ECU anticipates you to upshift or downshift, and will add extra fuel in anticipation for you to re-open the throttle body and engage the clutch to efficiently transfer into a higher RPM range). Spark timing and fuel curve are also modified in those cercumstances. Unless your syptoms are relatively extreme and random, don't worry too much.

it will drop soon as I stop but will stay reving until either I stop or put it in gear and back out