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914World.com _ 914World Garage _ intermittant idle problem

Posted by: markyb Mar 18 2012, 01:20 PM

I have an L-jet induction, and while driving and coming to a stop the idle will sometimes drop to 2K RPM and stay there, and sometimes it drops to about 1K. On a few occasions the idle stayed elevated for about 30 seconds, and then dropped to a lower idle speed. Even if I blip the throttle while in neutral, it still won't release to a lower RPM. After reading quite a bit regarding L-jet, does this sound like an intermittant problem with the AAV? The throttle cable is moving freely, so no hang-up there. If I ride the clutch down to below 2K RPM while coming to a stop it generally will result in a lower idle when I finally depress the clutch pedal.

I have a guide on testing the components, looking for a little help on where to start...

thanks

Posted by: markyb Mar 18 2012, 04:56 PM

update....I just started the car with a cold engine to see what it looks like under the hood, I noticed the short hose that goes from the throttle body to the AAR was kinked, so as a temporary fix I ty-wrapped it to keep the hose open. Went for a quick ride, and with a warm engine I noticed that the long hose from the throttle body to the Decel Valve was collapsed from vaccum(it looked normal with a cold engine, probably due to low vaccum at idle?). Can anyone explain the mechanics of the Decel Valve and how it operates?

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Posted by: dlee6204 Mar 18 2012, 05:11 PM

One thing you might want to check is that your throttle body/butterfly valve is closing all the way. With the engine running, manually push it closed and see if the idle drops. It might be gummed up and need cleaning or you might need a stiffer return spring.