Idle Air Control Valve - Revision history

Deggles: /* S1 Exige */

2016-09-20T18:54:54Z

S1 Exige

← Older revision		Revision as of 18:54, 20 September 2016
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	==S1 Exige==		==S1 Exige==
	The IACV is mounted underneath the airbox, in a bracket bolted to the engine block ~~with an M10 hex-head~~ bolt (~~17mm~~ socket)		The IACV is mounted underneath the airbox, in a bracket/clamp that is bolted to the engine block. Undo the long M6 bolt (10mm socket) to slacken the clamp and remove the IACV.

	===Location===		===Location===

Deggles at 18:51, 20 September 2016

2016-09-20T18:51:45Z

← Older revision		Revision as of 18:51, 20 September 2016
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	{{clr}}		{{clr}}

			==S1 Exige==
			The IACV is mounted underneath the airbox, in a bracket bolted to the engine block with an M10 hex-head bolt (17mm socket)

			===Location===
			[[Image:IAC_ExigeS1.jpg\|thumb\|left\|Idle Air Control Valve (S1 Exige)]]
			{{clr}}

	==S2==		==S2==

Deggles at 18:36, 20 September 2016

2016-09-20T18:36:04Z

← Older revision		Revision as of 18:36, 20 September 2016
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	*S1 K-Series engined Elises use a Rover EU2 Stepper IACV (Part No. Rover MLZ100090 ~~Lotus~~ A918E6011F or Bosch 0280140516)		*S1 K-Series engined Elises use a Rover EU2 Stepper IACV (Part No. Rover MLZ100090)
			*S1 Exige uses a Bosch IACV (Part No. A918E6011F or Bosch 0280140516)
	*S2 K-Series engined Elises use a Rover EU3 PWM IACV (Rover MDQ100170 Lotus A117E6069S)		*S2 K-Series engined Elises use a Rover EU3 PWM IACV (Rover MDQ100170 Lotus A117E6069S)

Deggles: added Lotus and Bosch part numbers for S1, fixed some typos

2016-09-20T18:33:41Z

added Lotus and Bosch part numbers for S1, fixed some typos

← Older revision		Revision as of 18:33, 20 September 2016
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	{{clr}}		{{clr}}

	*S1 K-Series engined Elises use a Rover EU2 Stepper IACV (Part No. MLZ100090)		*S1 K-Series engined Elises use a Rover EU2 Stepper IACV (Part No. Rover MLZ100090 Lotus A918E6011F or Bosch 0280140516)
	*S2 K-Series engined Elises use a Rover EU3 PWM IACV (Rover MDQ100170 Lotus A117E6069S)		*S2 K-Series engined Elises use a Rover EU3 PWM IACV (Rover MDQ100170 Lotus A117E6069S)


	If you are ~~suspiscious~~ that your IACV may be stuck/jammed, you can test it by disconnecting and reconnecting the [[ECU]] temperature sender with the car ignition on (but not running). If it can move, you'll hear it chatter as it seeks to a new position when you unplug the sensor.		If you are suspicious that your IACV may be stuck/jammed, you can test it by disconnecting and reconnecting the [[ECU]] temperature sender with the car ignition on (but not running). If it can move, you'll hear it chatter as it seeks to a new position when you unplug the sensor.

	==Fitting and removal==		==Fitting and removal==
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	=="Resetting" the iacv==		=="Resetting" the iacv==
	S1 (Stepper) The IAC Valve ~~postition~~ maybe reset by switching the ignition on disabling the ~~imobiliser~~ and pressing the throttle fully and slowly 5 times, it may also be reset with the Lotus check tool. This is detailed in section EMN page 14 of the service manual.		S1 (Stepper) The IAC Valve position maybe reset by switching the ignition on disabling the immobiliser and pressing the throttle fully and slowly 5 times, it may also be reset with the Lotus check tool. This is detailed in section EMN page 14 of the service manual.

	S2 (PWM) The S2 ECU cant measure where the IACV is so has to count the drive pulses it sends and remember the ~~poistion~~, then tries to return to a datum every ignition on/off. If it loses track e.g. battery disconnected the ignition needs to be switched on to position 2 and off several times to run the valve back to the datum.		S2 (PWM) The S2 ECU cant measure where the IACV is so has to count the drive pulses it sends and remember the position, then tries to return to a datum every ignition on/off. If it loses track e.g. battery disconnected the ignition needs to be switched on to position 2 and off several times to run the valve back to the datum.

	== External links ==		== External links ==

hbaumhardt: /* "Resetting" the iacv */

2010-02-12T09:57:31Z

"Resetting" the iacv

← Older revision		Revision as of 09:57, 12 February 2010
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	S1 (Stepper) The IAC Valve postition maybe reset by switching the ignition on disabling the imobiliser and pressing the throttle fully and slowly 5 times, it may also be reset with the Lotus check tool. This is detailed in section EMN page 14 of the service manual.		S1 (Stepper) The IAC Valve postition maybe reset by switching the ignition on disabling the imobiliser and pressing the throttle fully and slowly 5 times, it may also be reset with the Lotus check tool. This is detailed in section EMN page 14 of the service manual.

	S2 (PWM) The S2 ECU cant measure where the IACV is so has to count and remember the poistion ~~and~~ tries to return to a datum every ignition on/off. If it loses track e.g. battery disconnected the ~~ingnition~~ needs to be switched on to position 2 and off several times to run the valve back to the datum.		S2 (PWM) The S2 ECU cant measure where the IACV is so has to count the drive pulses it sends and remember the poistion, then tries to return to a datum every ignition on/off. If it loses track e.g. battery disconnected the ignition needs to be switched on to position 2 and off several times to run the valve back to the datum.

	== External links ==		== External links ==

hbaumhardt at 09:06, 12 February 2010

2010-02-12T09:06:16Z

← Older revision		Revision as of 09:06, 12 February 2010
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	[[Image:S2_K_Series_IACV.JPG\|thumb\|left\|Idle Air Control Valve (S2 K-Series)]]		[[Image:S2_K_Series_IACV.JPG\|thumb\|left\|Idle Air Control Valve (S2 K-Series)]]
	The '''Idle Air Control Valve''' (IACV), or '''stepper motor''', allows the electronic control unit ([[ECU]]~~, a.k.a. MEMS~~) to regulate the airflow to the engine independently of the driver's throttle input.		The '''Idle Air Control Valve''' (IACV), or '''stepper motor''', allows the electronic control unit ([[ECU]]) to regulate the airflow to the engine independently of the driver's throttle input.

	When the engine is idling ~~MEMS~~ uses this control (in parallel with ignition timing modulation) to compensate for varying loads that the engine must overcome to maintain the desired idle speed (i.e. friction, electrical load, A/C compressor load etc)		When the engine is idling ECU uses this control (in parallel with ignition timing modulation) to compensate for varying loads that the engine must overcome to maintain the desired idle speed (i.e. friction, electrical load, A/C compressor load etc)

	The IACV is also used to control airflow during load changes between positive and negative torque to provide a throttle damping function to improve the drivability characteristics of the vehicle.		The IACV is also used to control airflow during load changes between positive and negative torque to provide a throttle damping function to improve the drivability characteristics of the vehicle.
	{{clr}}		{{clr}}

	*S1 K-Series engined Elises use a Rover IACV (Part No. MLZ100090)		*S1 K-Series engined Elises use a Rover EU2 Stepper IACV (Part No. MLZ100090)
	*S2 K-Series engined Elises use a ~~different~~ IACV (Lotus ~~Part No.~~ A117E6069S)		*S2 K-Series engined Elises use a Rover EU3 PWM IACV (Rover MDQ100170 Lotus A117E6069S)

hbaumhardt: /* "Resetting" the iacv */

2010-02-12T09:04:09Z

"Resetting" the iacv

← Older revision		Revision as of 09:04, 12 February 2010
Line 34:		Line 34:

	=="Resetting" the iacv==		=="Resetting" the iacv==
	The IAC Valve postition maybe reset by switching the ignition on disabling the imobiliser and pressing the throttle fully and slowly 5 times, it may also be reset with the Lotus check tool.		S1 (Stepper) The IAC Valve postition maybe reset by switching the ignition on disabling the imobiliser and pressing the throttle fully and slowly 5 times, it may also be reset with the Lotus check tool. This is detailed in section EMN page 14 of the service manual.

	This is detailed in section EMN page 14 of the service manual.

			S2 (PWM) The S2 ECU cant measure where the IACV is so has to count and remember the poistion and tries to return to a datum every ignition on/off. If it loses track e.g. battery disconnected the ingnition needs to be switched on to position 2 and off several times to run the valve back to the datum.

	== External links ==		== External links ==

Mr Wiki at 12:08, 23 June 2009

2009-06-23T12:08:10Z

← Older revision		Revision as of 12:08, 23 June 2009
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	[[Category:S1]]		[[Category:S1]]
	[[Category:S2]]		[[Category:S2]]
	[[Category:Induction]]		[[Category:Air Induction]]

AndrewF: /* S2 */

2008-05-15T12:44:51Z

← Older revision		Revision as of 12:44, 15 May 2008
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	==S2==		==S2==
	Removal, cleaning and refitting is a 20 minute job. Unplug the loom attachment first. The valve assembly is held in place by four torx screws. The lower two are not visible and have to be located by feel. When the assembly comes free be careful not to drop the rubber seal. Detach the hose. Cleaned with copious amounts of carburettor cleaner spray (until the fluid runs clear). Fitting is reverse of removal, use silicon grease on the seal before reseating. Screw torque 1.5nm.		Removal, cleaning and refitting is a 20 minute job. Unplug the loom attachment first. The valve assembly is held in place by four torx screws. The lower two are not visible and have to be located by feel. When the assembly comes free be careful not to drop the rubber seal. Detach the hose. Cleaned with copious amounts of carburettor cleaner spray (until the fluid runs clear). Fitting is reverse of removal, use silicon grease on the seal before reseating. Screw torque 1.5nm.

			http://forums.seloc.org/viewthread.php?tid=166362&page=1#pid3289867

	===Location===		===Location===

AndrewF: /* S2 */

2008-05-15T12:43:22Z

← Older revision		Revision as of 12:43, 15 May 2008
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	==S2==		==S2==
	Removal, cleaning and refitting is a 20 minute job. Unplug the loom attachment first. The valve assembly is held in place by four torx screws. The lower two are not visible and have to be located by feel. When the assembly comes free ~~detach~~ the hose. ~~When removed it may be sooty and is cleaned~~ with copious amounts of carburettor cleaner spray (until the fluid runs clear). Fitting is reverse of removal. Screw torque 1.5nm.		Removal, cleaning and refitting is a 20 minute job. Unplug the loom attachment first. The valve assembly is held in place by four torx screws. The lower two are not visible and have to be located by feel. When the assembly comes free be careful not to drop the rubber seal. Detach the hose. Cleaned with copious amounts of carburettor cleaner spray (until the fluid runs clear). Fitting is reverse of removal, use silicon grease on the seal before reseating. Screw torque 1.5nm.

	===Location===		===Location===