High idle (1,500-1,700 RPM's)

[supergst]

-1998 GS-T
-High idle (1,500-1,700 RPM's)
-Checked IAC, it twitched when I put power to the motor, but the resistors are good.
-Replaced TB seals
-Smoke tested the vehicle to make sure there are no vacuum leaks after the TB seals were replaced, no leaks.
-Checked PCV valve
-Cleaned TB
-Cleaned FIAV valve
-Made sure slack is correct on throttle cable

I've run out of ideas, any insight?

P.S. - I heard spark plug wires could be a possibility, can this be the case?

 

[Calan]

Check this link out...it may help you:

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[stevo911]

IAC is not supposed to twitch even if resistors check out something mechanical isnt right,

 

[DSMTriad]

You might just have to adjust the idle switch(with the car on) thats what I did.

 

[98gst14b]

Make sure your idle switch isnt in too far it will act like a idle stopper if its in too far and raise your idle, also make sure your connection is good there (ie. if you unplug the idle sw. the idle will go up to about 1500)

 

[supergst]

You might just have to adjust the idle switch(with the car on) thats what I did.

Make sure your idle switch isnt in too far it will act like a idle stopper if its in too far and raise your idle, also make sure your connection is good there (ie. if you unplug the idle sw. the idle will go up to about 1500)

Is this for a 1g, or a 2g?

IAC is not supposed to twitch even if resistors check out something mechanical isnt right,

So, when power is put to the motor on the IAC, what is it supposed to do?

 

[stevo911]

IAC should move in and out freely if it twitchs its gone. Also while adding power make sure to put your finger on the plunger to add a little resistance it should move freely no "pops" or twitching.

 

[stevo911]

That idle switch they are talkin about is the Throttle Position Switch look around the throttle cable at the body youll see a little tab by the spring that pushes on a sensor,

 

[PIMking]

Try this, Take some carb cleaner and spray near the injectors and listen for the idle to climb. If not then you know thats good but I would also spray the intake manifold near were it mounts to the head.

My car did the same thing and it happened to be a bad intake gasket. once I replaced that all was good.

 

[spectr019]

Are you able to manually CLOSE the throttle, bringing the idle back down? If that's the case, another factor could be the cruise control. I had that problem, and my afc said that the throttle was actually around 4-6%. Switched out to a non-cruise system and that fixed it. If you want the cruise, just get new components and a new cable, see if that works.

Ben

 

[shanetalon12]

Make sure your idle switch isnt in too far it will act like a idle stopper if its in too far and raise your idle, also make sure your connection is good there (ie. if you unplug the idle sw. the idle will go up to about 1500)

you dont want that switch screw all the way in?