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Q: I have rough idle and shaking

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My 2005 neon sxt's idle air control valve is not getting power. Luckily the pintle is in the retracted position so I can get a halfway decent idle but it's less than desirable. I get a decent shake when stopped (no it's not the motor mounts, I have inspected them) but no engine shut off. Tried replacing the old valve and it dies immediately. Checked the voltage on the connector while the ignition is on and I get nothing. No visible damage to the writing that I can see. Isn't there a relay that can be changed out? I'm also getting a long time to start after the car has sat for a while. It always starts though. Engine only runs rough on idle. Getting a slightly rich fuel mixture. Not sure where to go from here.

Vehicle background Spark plugs, wiring and coil pack were recently replaced Alternator is less than one year old All belts except timing have been replaced New can shaft position sensor New battery Normal maintenance kept up with regularly

My car has 90000 miles.
My car has an automatic transmission.

The idle air control motor is powered and controlled by the engine computer. You will only get power and ground when the computer wants it to move. If the engine computer is not controlling it, then you may have a defective computer. The system should be scanned and any codes that appear should be diagnosed. The idle control valve may be shorted and burned out the circuit in the engine computer. Testing all codes will isolate the problem. If you would like to have your rough idling and shaking issue inspected, an expert mechanic from YourMechanic can come to your car’s location to diagnose the car and recommend a repair.

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