My idle is stuck at 3000 rpm I cleaned the IACV and still doing it. what should I try next?

 

Check for vacuum leaks, and check the fitv.

 

try adjusting the idle screw

 

There might be a crack on your intake manifold gasket..It happened to my gsr and my rev was bouncing up an down w/ high idle..changed that and cleaned the iacv..was perfect once again..

 

Things involved with idle control:

Idle control screw (throttle body)
function: allows more or less air directly into the intake manifold thereby raising/lowering the idle.
Recommendation: adjust the idle via this screw.


Throttle body vapor purge port (throttle body)
function: depending on make/model, it allows the fuel vapor from the charcoal canister purge solenoid entrance into the intake manifold.
recommendation: this port needs sealed shut, or alternatively sealed to the vapor purge solenoid (either way, no vacuum leak).


Throttle body gasket (between throttle and intake manifold)
function: keeps the throttle/intake manifold sealed without vacuum leaks.
Recommendation: make sure its sealed, no leaks.


Intake manifold air ports (intake manifold)
function: miscellaneous vacuum points (including cruise control vacuum line, fuel pressure regulator vacuum line, purge control vacuum line, *more*)
Recommendation: Make sure all the ports are sealed shut, or alternatively sealed via their corresponding vacuum lines to the peripheral devices.


Intake manifold gasket (between engine and intake manifold)
function: keeps the intake manifold/engine head sealed without vacuum leaks.
Recommendation: make sure its sealed, no leaks.


Fast idle thermo valve, FIT (bottom of throttle body)
function: allows more air into the intake manifold via a thermowax plastic insert thereby compensating for colder climates (and cold starts).
Recommendation: Depending on you global position/typical environment...open the end plate and tighten the white insert all the way, thereby allowing no air through.


Idle air control Valve, IACV (back of intake manifold)
function: controls air flow during all stages of driving, opening and closing to keep intake manifold vacuum stabilized.
Recommendation: Clean, test, alternatively replace.


Throttle position sensor, TPS (side of throttle body)
function: allows the ecu intimate knowledge of the current angle at which the throttle plate is situated. This allows the ecu to compensate for many things including idle conditions, ecu tables (ignition and fuel), etc.
Recommendation: Test the center wire (make/model dependant) with your engine off, key in the ON position. This value should be 0.5 volts closed throttle and 4.5 volts wide open throttle.


Manifold absolute pressure sensor, MAP (top of throttle)
function: allows the ecu knowledge of the current vacuum value inside the intake manifold. This value is also used in conjunction with the TPS for the ecu's control of ecu tables and the sort.


ECU, PCM, (passenger kick panel)
function: overall control of the engine and peripherals.
Recommendation: check all else first... twice.


Coolant lines
function: in this context, the coolant lines are ran through the FIT and IACV to warm the thermowax inserts in order to lower the amount of air going through the individual valves. This helps stabilize the volumetric airflow for a warmer climate/warm engine.
Recommendation: Make sure they are tight with no kinks/hard unusual bends.


Coolant
function: Cools the engine. Warms the IACV and FIT valve thereby closing the thermowax inserts.
Recommendation: Make sure your coolant is topped off an your lines of bled of air (bleed the system). This will make sure the IACV and FIT get to appropriate temperature at appropriate speeds thereby not confusing the ecu (by the quantity air throughput.


Wiring (IACV, MAP, TPS, ECU)
function: to power and read the appropriate values accordingly.
Recommendation: Check to be sure signals are appropriate, plugs are appropriately situated (i.e. it is not an uncommon ocurrance in HT to have the TPS and MAP plugs switched, alternatively the IAT and IACV plugs switched). Get an electrical schematic for your vehicle/engine and test all nodes for continuity to their respective locations.

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Ignore what you need to, this is a generic write-up. I'm leaning towards vacuum leaks and FIT... Good luck!

 

its more then likely a big vacume leak on the intake manifold. I remeber this happend to me when i put my vtec head on my ls. i was not familiar with the gsr intake manifold and i had a catch can setup off the valve cover and i never hooked the pcv system up on the bottem of the intake manifold. It idled at about 3500rpm. Its defenetly a big vacume leak. Probably not just a small vacume line leak.