MY HONDA CIVIC IS ERATIC IDLEING - Civic Honda Cars & Trucks

Sounds like a poor connection at the battery or alternator. You need to make sure there is no corrosion or faults in these connections. If there is no fault there then you likely have a ground problem. Find your engine/Chassis ground, make sure it's tight and again free from corrosion and fault. Leaking battery acid can eat wires on the possitive and ground causing issues. Also if the car has been in an accident it could also have damaged or lossened the ground.

The tacho is fed from the ignition system, so you should expect a problem with either connections to the ECU or a failed ECU.

idleing sincer sounds as if its going bad located around carbrater.

If it had been a carberated model I would say the choke is not working. I still suspect that your vehicle is running too lean at start up. Have you had it hooked up to an OBD (On Board Diagnostic) tester to see what error codes it may display? I think that a sensor is malfunctioning and not allowing enough fuel to be delivered at start up (warm up). Let me know so I can help you further. Thanks.

Possibly a clogged catalytic converter, or somthing with ignition from the coil to the spark plug.

maybe a problem with your brake booster or brake vacuam line, this would also cause eratic idleing. Can you hear an air leak?

could be your clutch is not fully disengauging or on its last leggs check if you can ajust the freeplay at the clutch cylinder thats if your car is a manual

possible ur idleing turn ur car on then slowely turn it

Quite possibly the air conditioning compressor clutch bearing. I've seen a couple of these go bad now. Have the belt removed and see if the noise goes away.

did you check to see if your intake gasket is properly seated, and also what kind of idleing is it...if it seems its not getting enough gas check the idle control mod. or do a good clean on your injectors.