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Idle Air Control Valve

For the past month or so, my 2002 Kia Sedona has been stalling/dying whenever I stop at lights or signs. We’ve gotten the alternator fixed, gotten a new battery, replaced the ignition coils, but still have the same problem. A friend of mine says that there is probably an issue with the idle air control valve and suggests I replace it. Looking online, it seems like I can possibly just clean it out, but I don’t know where to begin. Where exactly is the IAC valve and is replacing/cleaning it a basic DIY job?

Try this.

Its a fine video - but its about a TPS rather than IACV.

Its really hard to tell from that video, and I’ve never looked under the hood of a Sedona, but it looks like the IACV maybe right there on the front opposite the TPS. Either way it is attached to that same hunk of metal as the TPS - which is the throttle body. If that is it in the front it should be a fairly easy DIY job. Get a can of throttle body cleaner and a new IAC gasket and you’d be good to go.

Here’s a guy cleaning an IAC, but not on a Sedona:

This guy pulled the throttle body off, but you probably don’t have to.

Has the check engine light ever come on? Regardless, you should check to see if any trouble codes are stored in the vehicle computer. If there are any, they could point you in the general direction.

Does it only have problems when the brakes are applied? if so it could be a bad brake booster vacuum line.

Suggest don’t jump to the conclusion the problem is the IAC. There’s several things that could cause the symptoms you are experiencing. The IAC operation is identical to if you pressed on the gas pedal a little bit. If you press on the gas pedal a bit when you come to a stop, does the car not stall out then? If it still stalls, the IAC isn’t the problem. And the IAC – at least that is how it works in my Toyota – is supposed to increase the idle only under certain condition, like when you turn on the headlights, or the air conditioning. Or when the engine is cold. If you arent doing any of those things and the car is still stalling out, I doubt it is the IAC. On my car, the IAC inputs are routed through something called the idle-up diode, which is the way the electronics decides if one or more of the operatting conditions (as above) that are supposed to energize the IAC has happened.

  • Has the car had a tune-up where the spark plugs are replaced, the timing checked, the air filter replaced recently? If not, that’s probably where I’d start first.

The check engine light has been on constantly for a few months now despite whatever we’ve replaced.

Spark plugs have been replaced and we are changing the air filter tomorrow.

The headlights or the AC aren’t on whenever the car stalls. And it’s only when we’ve braked and come to a stop that it stalls. However, there are instances when we’re shifting from park to drive that once it’s on drive, it will just die.

The engine also responds to vacuum. Check all the vacuum lines. This adds extra air and throws off the air mix due to telling the map sensor that less air is coming into the intake. A bad engine coolant temp sensor is easy to check but a remote possibility. Sounds like the engine mix at idle is too lean. The IAC on many cars used to push the throttle plate just a nudge given various issues, depends on the specific issues the manufacturer had with the system.

“The check engine light has been on constantly for a few months now despite whatever we’ve replaced.”

Oy. That means there are error codes. Many auto parts stores will read these for free. Get them and report the exact codes - format: “P1234”

Cleaning an IACV is usually easy, cheap, and not a bad maintenance move whether it helps or not. But, holy cow, report the codes.