If your 1999 Ford Contour has an idle speed problem, it's almost certainly due to a problem *elsewhere* in the system, not a need for adjustment. Here's what you should do:
1. Check for trouble codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in the PCM. These codes will pinpoint potential problems. Common causes of idle issues include:
* Mass Airflow Sensor (MAF) issues: A dirty or faulty MAF sensor will provide inaccurate readings to the PCM, leading to an incorrect idle. Clean the MAF sensor carefully (with MAF sensor cleaner, not regular electronics cleaner) or replace it if necessary.
* Throttle Position Sensor (TPS) issues: A faulty TPS can also cause erratic idle. These often need replacing.
* Idle Air Control (IAC) valve problems: The IAC valve controls the air entering the engine at idle. It can become dirty or faulty, causing rough idle or stalling. Cleaning it (sometimes with MAF cleaner) or replacement might be needed.
* Vacuum leaks: Any leaks in the intake manifold vacuum system can cause a low or erratic idle. Inspect all vacuum hoses and connections for cracks or looseness.
* Dirty throttle body: A dirty throttle body can restrict airflow and affect the idle. Clean it thoroughly with throttle body cleaner.
* Faulty PCV valve: A clogged PCV valve can cause excessive crankcase pressure, affecting idle.
2. Check engine components: Ensure that the ignition system is working correctly (spark plugs, wires, distributor cap and rotor if equipped). Also, check the condition of the fuel injectors and fuel pressure.
3. Professional help: If you can't identify the problem using the above steps, take your Contour to a qualified mechanic. Attempting to adjust something you don't understand on a modern fuel-injected engine could cause more harm than good. The PCM controls the idle, and improper intervention can lead to serious engine damage.
In short: Don't try to "adjust" the idle. Diagnose and fix the underlying problem causing the idle issue.
