Location Of Idle Air Control Valve On 1997 Honda Accord V6

What are some symptoms of a bad idle air control sensor?

Idle air control valves open to allow more air to "leak" into the intake, raising the engine rpms, or close when not needed. When your AC compressor kicks in or power steering is activated as you suddenly turn the steering wheel, the sudden drag on the drive belt will bog down the engine. These systems send a signal to the engine computer telling it they are active and it then signals the IAC valve to open, which increases the engine speed. Without this occurring,  the engine could struggle, or die. The IAC valve can cause weird idle issues, mess with throttle functionality or cause the car to die. Sometimes they fail, get stuck or just get all carboned up. Sometimes people have success at cleaning them, but generally it is best to replace them when bad. Idle issues and even problems with the IAC valve may not be due to the IAC valve being bad itself. An idle issue does not mean the IAC valve is bad. It is best to pay close attention to how the vehicle is acting, and then communicate that clearly and as completely as possible to your mechanic. Intermittent problems can be very hard to diagnose. Details will help. Knowing more about the vehicle in question and its symptoms (in detail) will also help in understanding more about what it is doing.

What are the symptoms of having a bad ignition control module?

Hard starting and no starting. Especially if the hard or no start condition happens after the car has been driven awhile and is fully warmed up and stalls. Then if you let the car sit until it cools off and it starts right up there’s a very good chance it’s due to a bad module. Like Jon said you should have it tested by someone who knows how to or risk breaking down at the worst time in the most far away place. Good luck and hope this helps.

What does a mass air flow sensor do? Can a car run without one?

Mass Airflow Sensors (MAF) report the amount or density (Mass) of the air entering the engine to the Powertrain Control Module (PCM).There are various designs of MAF sensors, but the most common by far is the hot wire MAF sensor. The hot wire MAF has two wires. One wire is heated and the other is not. The computer (PCM) calculates the mass of the air entering the engine by how much current is required to keep the hot wire about 200 ℉ hotter than the cold wire. When the temperature difference between the two sensing wires changes, the MAF will either increase or decrease the current to the heated wire. This equates to more air into the engine or less air into the engine.While the vehicle may run with a dirty or broken MAF, it will not be efficient and may cause mechanical damage to the engine due to running in a lean condition.A failed MAF sensor may not send any airflow information to the PCM. This prevents the PCM from accurately controlling fuel, which will result in an engine that either will not idle or will idle roughly. If the MAF is still sending information, but the information is wrong or garbled, the PCM will send the incorrect amount of fuel through the injectors. This will lead to a consistently rich or lean condition. You will notice this as a change in fuel consumption or black smoke coming out of the exhaust pipe. In either case, replacment of the MAF is required.A dirty MAF will give symptoms of rich at idle and/or lean under a load. A MAF that has a contaminated hot wire can come from spider webs, potting compound, oily dirt that comes from an over-oiled reusable performance air filter, or other sources. Anything that acts like insulation on the hot wire will cause this issue. This is not a failure of the MAF, the fix is as simple as cleaning the MAF sensor with an approved MAF sensor cleaner (Yes, this is a real thing).As a short term, limp home thing, yes some vehicles can operate with a failed or disconnected MAF. But it is a needed part for fuel injected engines that were designed with one in the control system. Some injection control systems do not have a MAF, and no carburated engines have them.

Is it normal for a car's idling RPM to decrease when the air is turned on?

Sure, these devices take energy to run. I have seen quotes where a car Air Conditioner compressor and fans would take 6 horse power to run on a hot day. A defroster is using the Air Conditioner compressor to dry out the air and defrost / defog the window. Either way, you’re running the compressor which takes energy to do.

Why does my car idle at a really low RPM while stopped, and start shaking?

You may have a misfire, a vacuum leak, or a clogged/faulty idle air control valve. It could be a couple other things, too, but those are the most common and first things you should explore. This is because:If you have a misfire, one of your cylinders is not working and while that may be less noticeable at higher speeds when the engine is spinning really fast and the throttle is wide open, at lower speeds the difference is more apparent.If there is no misfire (and no codes / check engine light), the problem is most likely air related. This could mean a vacuum leak from a hose or the intake manifold itself. Or, commonly, it could be that your Idle Air Control Valve is clogged or not working well. The engine monitors via sensors how much air is coming in vs engine speed and uses that to control fuel injection and ignition timing.If it's a vacuum leak, the engine is getting more air than it thinks it is and that is causing a 'lean' fuel/air ratio.If the IAC valve (and its passages around the throttle plate) are clogged up, the engine thinks it's getting more air than it really is at idle with the throttle plate closed (foot off the gas), resulting in a 'rich' fuel/air ratio.All of these scenarios will probably cause some sort of engine code and checking them should be your first step. Note that an oxygen sensor code will be indicitave of one of the above 'air' situations because it detects how rich or lean the ratio is.