Idle Valves

Archives Known Problems
1

Can anyone tell me where the idle valve is, and if it’s easy to get at and work on?Still can’t get the car to idle when it’s restarted from warm. Next step is the idle valve…

2

It sits under the throttle bodies, look for the blue silicon pipe work and follow it to a bloody huge unit !!Have you tried resetting it? switch on the ignition and press the throttle pedal all the way slowly 5 times then switch it off and restart.

3

Thanks, will give it a try. How do you know about the resetting? and what’s it supposed to do?Mark

4

The resetting trick was something i just picked up on and committed to memory for future use [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]The idle valve is just an open and shut motor, the ecu does not know how far it is opened or closed but it knows by reference values roughly where it is, i.e. it knows the value when closed is say 0 and when fully opened is 100, when you switch on the ignition the valve opens and the ecu presumes it always opens the same amount at value 100.It will closed it down from as the car warms up to say 40 for a steady idle.Now if the motor sticks, and they do quite often, at switch on the valve opens but sticks at 75% opening, the ecu will still think it is at 100 and close it down to 40 by its own counter, however in reality the valve has now closed to far and the car does not have enough air to idle and stalls.The same thing can happen in reverse which makes the idle speed to high, the ecu and iacv are out of step.A good clean of the IACV and reset on the ECU will generally sort you out.HTH

5

Thanks very much. I’ve got a lotus field engineer looking at the car soon to give his thoughts, but from what you’re saying that makes perfect sense. A friend thought it might be the potentiometer?By the way, I tried the reset trick and it didn’t work.Mark[This message has been edited by Sparky74 (edited 10 November 2002).]

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6

I had the same problem after fitting the 190 ECU. The ECU has been reset many times but nothing. Then i just played a bit withthe throttle body screw and fixed everithing.Now is perfectly working, with hot and cold wether, with hot and cold starts.Nicolas

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