My Honda starts just fine, runs for 5-10 seconds, and then the idle drops, it bogs down, and dies. I can immediately crank the car again and it will crank and start up like normal, but again, after 5-10 seconds, the idle drops, the car bogs down, and stalls. Ive checked the alternator and the battery and replaced the battery with a brand new one. The alternator is fine. I replaced the fuel pump/fuel filter and the car still does the same thing. I can try giving gas to the car to idle it higher and it will still stall. The immobilizer light does not flash or stay on, so the key should be working fine and I dont believe it is an issue with the key programming.
My car has roughly 235000 miles.
My car has an automatic transmission.
What you are describing sounds like a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer and will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. This is also an important function when starting the motor as it allows the motor to run and idle on it’s own once the motor fires. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed while adjusting the air/fuel ratio constantly to allow this to happen smoothly. When the engine RPM drops below the normal range of about 800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.
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