98 Honda civic ex? Rpm meter moves by itself?

Question

I have a Honda civic. The engine check light is on. When the car is in park or neutral the rpm meter will go up and down by itself. And when I'm driving it'll so the same causing the car to jerk back and forth. What is causing this? Any help would be appreciated thanks :)

Answer 1

Go to your local auto parts store and buy/borrow a Onboard Diagnostic Scanner (ODB II) and plug the cable to the interface port underneath the dashboard on the driver's side.  Then repost your question with the error code associated with your check engine light.

The problem could be anything but the error code should help break it down to the actual sensor triggering the check engine light.  There are many sensors in your car that tell the computer when to automatically increase or decrease your rpm regardless of whether or not you're pressing on the accelerator.

For example, if you're MAP (manifold air pressure) sensor near your throttle housing is faulty and sends the wrong signal of air pressure, your rpm can increase on it's own as if you're pressing the gas pedal.  

Or if your sensor incorrectly detects that your engine is very cold, it can also increase your rpm by itself in attempt to heat up your engine so that it can reach normal operating temperature.

Good luck!

Answer 2

The check engine light means that one of your fuel injectors are bad and that could be causing all your problems.

Answer 3

the check engine light  should be a clue. get it scanned and that should give you the information. it sounds like you have a failing distributor.