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Discussion Starter #1
I just got this GT a couple of weeks ago. It has a K&N CAI, but that's it on the engine. When I am sitting with it out of gear, the RPMs go back and forth between like 900-1K and 300-500. It will go down, and then idle back up. It still does this with no accessories on. What could be my problem?
 

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I have a 2000 GT and it stays around 1000 when I'm coasting in neutral. And when I come to a complete stop with it in neutral, it stays around 700-800. I'd clean your IAC first, if that doesnt work, make sure your not using crappy gas, and then maybe change the plugs. More than likely the prob is with your tb and iac.
 

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I have a 2000 GT and it stays around 1000 when I'm coasting in neutral. And when I come to a complete stop with it in neutral, it stays around 700-800.
If you back out the set screw on the TB (close the blade a bit more) it should fix that issue.
 

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i wouldn't screw around with the setscrew on the throttle body. clean the IAC first. check for codes. my car was doing the same thing for a while. i cleaned the IAC real well and it went away. a few weeks later, it started again, and i checked for codes. turns out my Throttle Position Sensor **** itself. replaced it, and no more idle probs...
and the CAI doesn't need a tune on our cars...
 

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Discussion Starter #7
Thnks! I'll clean my IAC tomorrow, and if that doesn't fix it, I'll take it down to autozone and see if there are any codes.
 

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just FYI, i think i paid something like 50 bucks at Advance Auto for my TPS...
 

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is your check engine light on?
 

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check all those above + make sure eveything around your intake and pvc are properly sealed and connected. my jlt came lose and my rpms went bonkers.
 

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It could have a small air leak which would cause it to hunt for idle. You can also try cleaning the mass air sometimes the oil from the filter gets on it. I've had to clean mine several times. Just adding to th epossibles that I've found.
 

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It could be 1 of a 1000 different things...

Clean your IAC
Check your plugs
Check your COPs
Check for a vacuum leak
Check EGR gasket
Check Intake Manifold gasket
Check throttle body gasket (between tb and intake)
Check exhaust manifold gaskets
Replace fuel filter
Easy way to check gaskets is to get a cheap bottle of bubbles...pour it around areas you suspect a leak, if it bubbles you have a leak...you can use soapy water but bubbles show up better.
 
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