If your idle speed is too high or too low, the problem lies elsewhere. Possible causes include:
* Dirty Throttle Body: A dirty throttle body can cause erratic idle. Cleaning it is often the first step in troubleshooting idle problems.
* Vacuum Leaks: Leaks in vacuum hoses can disrupt the engine's idle. Inspect all vacuum hoses for cracks, holes, or loose connections.
* IAC (Idle Air Control) Valve: This valve controls the amount of air entering the engine at idle. A faulty IAC valve is a common cause of idle problems. It may need cleaning or replacement.
* MAF (Mass Air Flow) Sensor: A dirty or faulty MAF sensor can provide incorrect information to the PCM, leading to incorrect idle speed.
* TPS (Throttle Position Sensor): A malfunctioning TPS can also cause idle problems.
* Engine Problems: More serious issues like a vacuum leak in the intake manifold, faulty sensors or other engine issues could be to blame.
Instead of trying to adjust the idle speed directly, you should:
1. Consult a repair manual: A Haynes or Chilton manual specific to your 1992 Chrysler Fifth Avenue will provide detailed troubleshooting steps and diagrams.
2. Have a professional diagnose the problem: A mechanic with experience in older vehicles can properly diagnose and repair the underlying issue causing the incorrect idle speed. Trying to fix this yourself without the proper knowledge and tools could lead to more expensive repairs.
3. Use a scan tool: A scan tool can read the PCM's diagnostic trouble codes (DTCs), which can pinpoint the cause of the problem.
Attempting to manually adjust the idle on a computer-controlled engine like that in a 1992 Fifth Avenue is strongly discouraged. Focus on diagnosing and fixing the root cause of the idle issue instead.
