help me help me
i want the reason for this problem in rpm meter in my car is unstable
...sounds like a vacuum leak, do take it to have the the trouble codes read, your parts store should be able to do this for no money, then we's start to get a clue. help us help us by providing a bone to chew on.
When you get your trouble codes read, ask them to check the RPM output of the ECU. If that output is steady, your gauge is bad.