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I cannot reduce the idle speed by adjusting the screw of the AAC. Is there any method to check the AAC? Right now my car is idling at 1500 rpm. THE CAR RUN FINE EXCEPT FOR THE HIGH IDLE RPM. Thanks for any advice!!!!
 

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Re: Idle stuck at 1500 RPM !!!! Cannot lower it by adjusting the

Look through this, your answer lies somewhere within it.

<http://300zx-twinturbo.com/manual/efec/064.gif>

<http://home.swipnet.se/e-solutions/IdleTech.html>

Basically either you have vaccum leaks, fuel injector problems (search for fuel injector testing), a bad idle adjusting unit, tps is off, dirty trottle bodies, or temp sensor is gone. If it hasn't been done recently, go ahead and change the temp sensor (14 bucks) and clean your throttle bodies via <http://www.twinturbo.net/ttnettech/tb/tb.html>, do cheapest/easiest first. Turning the screw alone does nothing, you have to unplug the sensor connected to the unit. It is yellow on my car i believe and attatches from the top/towards firewall side a few inches behind the idle adjusting screw. Unplug it, change idle to the one you want, then plug it back in. At the end of the idle adjusting unit, there is a hose that then goes about another 6" to a foot to the rear of the balance tube that stretches over the motor going from the top right of the driver;s to the passenger's side of plenum. You can spray WD-40 in there to try to get some build up out of the unit while the car is idling also.



Post Edited (Feb 14, 3:40am)
 

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Re: Idle stuck at 1500 RPM !!!! Cannot lower it by adjusting the

Zlove57, I did unplug the yellow plug before making the idle adjustment but the car still idle @1500rpm. All the parts that you mentioned are working except the hose you described I do not see it in my car (93tt, auto). I just did a plenum pull, replaced all the injectors and bypass the water cooling aparatus for the TB. I connect the vacuum hose from the balance tube of the driver side directly to the hose that come from the front part of the car (carbon canister?). Could that be a problem?
 

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Did you paint mark the vac lines ...

and their attachment points before removing the plenum? If not then you may have a couple of lines mixed up. On the drivers side starting at the TB you have a vac line that attaches to the port that runs under the TB this runs to the cannister purge port. Working back there is a line that attaches to the air box on the plenum that runs to the left side recirculation valve. Now there is a line that runs along the fuel delivery tube that attaches to the balance tube that should be connected to the front port on the PRVR solenoid. When dissassembling the plenum it is allways a good idea to paintmark the vac lines and the connection points with matching marks. That way there is no guess work when reassembling the plenum. Make sure all the vac lines are connected properly then post what you find.
MaxDoc
 

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Re: Idle stuck at 1500 RPM !!!! Cannot lower it by adjusting the

There is a drawing in the factory service manual that shows the vacuum galleries and how they are connected. It's on page EF & EC - 12. Very helpful when I was reassembling after my injector replacement.
 
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