Fast Idle

[nazrin]

Nubira 97 manual,

Ok, I have a fast idle about 1500-1800, with the engine light on. I took it into a hole in the wall to have looked at to have a service (cleaned injectors/new plugs/new fuel filter/ new air filter) and have a diagnostic done while the engine light was on. He didn't tell me much he did not speak English so I was told the stepper motor that controlled the idle needed to be replace soon, this item is call I believe "fast idle relay, or idle modulator" not really sure, buy anyhow the idle went down for a week after he removed it and clean it but went back to the high idle afterwards. I did some testing myself to look for a induction leak to rule out this stepper motor, I took the boot off the intake before the throttle valve and put my hand over it to seal it off and the motor shut down in less than 2 sec and the vacuum that was left stayed there for a few minutes. I felt sure no leaks. I then turn the car back on and ran my finger over the port that lead to the idle modulator valve and was able to restrict the air being by-passed around the throttle valve and bring down the idle to a normal level and held it for a few minutes. The amount of air I was pinching off had to be 4-5 hundred times less than what the idle modulator was allowing to be bypassed so I was sure the problem was at this control point.

The real question is :

Is this stepper motor faulty, or is the device that sends information to it for its proper function faulty, resulting in this device (stepper motor) working to wrong information? If the second it true than what would be this faulty device?

One other point I just thought of is:

When I removed this idle modulator from the throttle body, there would be your black soot on the needle end of the plunger and you can see a very noticeable clean ring around it, showing the point the needle would seat itself on the inside housing to seal itself off. If this is the cast then you would think this thing is sealing itself when it wants to and maybe something else is telling it to not work properly. I don't know. Just more information.

[nazrin]

fixed the problem by replacing the stepper motor for the idle control