Tracker 99 idle at 600 on "P"arking and on "D"rive after cleaning the IAC valve

[ar_156]

It's a Tracker 99, 1600cc, automatic

When starting the car with the engine cold the idle goes to 1200, after warmming within 3 min it goes to 800 when the gear is in "P"arking position or "N"eutral, but when I change it to "D"rive with the break pressed (like when you stop when trafic light is in red) the idle goes to 600 and the car starts vibrating, it runs ok but when stoping with the gear in "D" the idle goes to 600 and the car vibration is unconfortable, at this moment if I change the gear to P or N the idle goes up to 800 and the vibration dissappears.

I took down and cleaned the IACV but now... when I start the engine cold the idle goes to 1200, after warmming it goes to 600, no matter the gear position is in P or N or D it just stays in 600! when in P or N the idle is 600 and no vibration, when in D the idle is 600 and the car vibrates.

What should I do?
Adjust the Idle Speed? how? where is the Idle Speed Controller knob?
Try to clean it again (I used half bottle of Intake cleanner)?

[fordem]

There is no idle speed adjustment knob, it's all done by the computer, through the idle speed control.

[ar_156]

Originally Posted by fordem

There is no idle speed adjustment knob, it's all done by the computer, through the idle speed control.

Is the Idle Speed Control the same Idle Air Control?

Any fix?

Thank you

[fordem]

Idle speed control, idle air control - different terms same device - the fix MIGHT be a replacement. Is yours defective?

On a 1.6 Tracker, the ISC is a electrically controlled, motorized valve just below the throttle body - cleaning the valve passages will only help if the valve passages are clogged, replacing the valve will only help, if the valve is defective - the problem could just as easily be the ECU or the harness.

[ar_156]

Originally Posted by fordem

Idle speed control, idle air control - different terms same device - the fix MIGHT be a replacement. Is yours defective?

On a 1.6 Tracker, the ISC is a electrically controlled, motorized valve just below the throttle body - cleaning the valve passages will only help if the valve passages are clogged, replacing the valve will only help, if the valve is defective - the problem could just as easily be the ECU or the harness.

I cleaned the valve and it seems to be working (on cold start it rise the idle to 1200 then when warm it goes down and stay on 600-650 whithout fluctuations when stoped (too low but seems to be doing the regulations)). How may I adjust idle on 850 in stead of 600?

Is ECU the Engine Control Unit? where is it? how to adjust it? where is the harness?

Please help, THANK YOU

[fordem]

Try unplugging the ISC valve and starting the car from cold - does it still idle at 1200 rpm and then drop? Do you still think the ISC is working?

[ar_156]

Originally Posted by fordem

Try unplugging the ISC valve and starting the car from cold - does it still idle at 1200 rpm and then drop? Do you still think the ISC is working?

I pulled the electric connector then the idle goes up to 1800 rpm cold and warm, then I plug it then it goes down to 600 warm. What does it mean? is the valve working?

[fordem]

Sounds that way.

[ar_156]

so if the valve is working and clean, why the idle stays at 600? any reset or adjustment method?

Is ECU the Engine Control Unit? where is it? how to adjust it? what and where is the harness?

[fordem]

The ECU is the computer that manages the fuel injection system, it's located under the glove box, the harness is the wiring connecting the ISC to the ECU, there are no adjustments - you EITHER have an ISC problem OR one of the other sensors is sending incorrect information back to the ECU causing it to set a low target idle.