A fluctuating or incorrect idle speed on a '93 Acclaim usually points to underlying problems, not just a need for adjustment. These problems could include:
* Dirty Idle Air Control (IAC) valve: This valve regulates airflow at idle. A dirty valve can cause erratic idling. Cleaning it with throttle body cleaner (following instructions carefully) is often a first step.
* Vacuum leaks: Cracks in vacuum hoses or leaks in the intake manifold can cause low or fluctuating idle. Inspect all vacuum lines for damage.
* Faulty Throttle Position Sensor (TPS): This sensor tells the ECM the throttle position. A malfunctioning TPS can cause a variety of problems, including idle issues.
* Dirty Mass Airflow Sensor (MAF) sensor: A dirty MAF sensor will provide inaccurate readings to the ECM, impacting fuel delivery and idle. Cleaning this sensor (carefully, with MAF sensor cleaner) can help.
* Faulty ECM: In rare cases, the ECM itself might be faulty. This is a less likely cause but should be considered if other issues are ruled out.
* Other Sensors: Various other sensors contribute to the idle control system. A malfunctioning sensor (like the coolant temperature sensor) could disrupt the ECM's calculations.
Instead of trying to adjust the idle speed directly (which is not possible without specialized tools and knowledge), you should:
1. Start with the simple checks: Inspect and clean the IAC valve and MAF sensor. Check all vacuum lines for leaks.
2. Consult a repair manual: A Haynes or Chilton repair manual specific to your 1993 Plymouth Acclaim will provide detailed diagrams and troubleshooting steps.
3. Use an OBD-II scanner: If you have access to an OBD-II scanner, it can read diagnostic trouble codes (DTCs) which might pinpoint the problem. Many auto parts stores will scan your car for free.
4. See a mechanic: If you're not comfortable with DIY car repair, take your Acclaim to a qualified mechanic. They have the tools and expertise to diagnose and fix the underlying problem causing the idle speed issue. Attempting to "adjust" something you don't understand can cause further damage.
In short: Don't try to adjust the idle speed manually. Fix the underlying cause.
