What's wrong if a 1993 Toyota Camry is constantly running sluggishly and at times it begins to lose power the rpms jump or the vehicle dies?

1. What causes a car to idle up and down?
2. What does it mean if your car revs on its own?
3. What happens when idle control valve goes bad?
4. What are the signs of a bad idle control valve?
5. Why does my RPM go up and down while idle?
6. Why does my car engine rev up and down when in park?
7. What causes engine over revving?
8. Why is my engine revs high without acceleration?
9. Why is my automatic car revving high?
10. Where is the idle control sensor located?
11. How much does an idle control valve cost?
12. Can you drive with a bad idle air control valve?
13. How do you clean the idle air control valve on a Toyota?
14. How do I reset my idle air control valve?
15. What happens if IAC is stuck open?

What causes a car to idle up and down?

If an engine is not getting enough fuel (this is called “running lean”), due to fuel pressure (regulated by the fuel pump and regulator), restricted fuel injectors, a vacuum leak or really anything that throws off the fuel mixture going in to the engine, this can cause the surge.

What does it mean if your car revs on its own?

A vacuum leak or a broken idle air control valve are two of the most prevalent causes of a car revving in neutral. When the gearbox is in neutral, a vacuum leak may let unmetered air into the engine, causing the idle to remain high. A broken fuse might cause an automobile to rev when it is idling.

What happens when idle control valve goes bad?

When the idle air control valve fails, it inhibits the flow of air through the engine. When the car can't receive air, it leads to engine stalling. The severity of this symptom can range from occasional stalling at first, to stalling immediately after ignition.

What are the signs of a bad idle control valve?

Common signs include irregular or unusually high idle speed, the Check Engine Light coming on, and stalling while idling.

Why does my RPM go up and down while idle?

If the engine can't keep idling, it will continue trying to get it revved up to compensate. The cause of the erratic engine you're experiencing could be a vacuum leak, sensor failure, or an EGR system malfunction.

Why does my car engine rev up and down when in park?

A vacuum leak, sensor that has failed, or an EGR system malfunction could potentially be the cause of the erratic engine you're experiencing. ... For this vehicle, the engines are very sensitive to vacuum leaks in the intake air tube, between the mass air flow sensor and the throttle body.

What causes engine over revving?

If an engine goes overspeed, commonly called "over-revving", damage to the piston and valvetrain may occur when a valve stays open longer than usual. Valve float can possibly result in loss of compression, misfire, or a valve and piston colliding with each other.

Why is my engine revs high without acceleration?

Transmission slipping, or gears slipping, is a common transmission problem and a real cause for concern. ... If your engine revs up as you press down on the accelerator but your vehicle doesn't accelerate as per usual or as you would expect, it's a troublesome sign that can lead to a full-blown transmission failure.

Why is my automatic car revving high?

In automatic vehicles, transmission fluid is used to carry power from the engine to the transmission. ... If the transmission fluid begins to leak, your car will start to rev to higher levels (due to torque converter or gearbox band slippage). This may be accompanied by delayed or erratic gear shifts.

Where is the idle control sensor located?

The IACV is usually located on the intake manifold near the back of the throttle body. Before starting the cleaning process, be sure the vehicle is not running and that the engine is cool.

How much does an idle control valve cost?

The replacement cost of an idle control valve is anywhere from $120 to $500. The cost of the parts alone will be between $70 and $400+, depending on the make and model of your vehicle. The labor cost should only be around $50 to $100 because it doesn't take that long to remove and replace the old idle control valve.

Can you drive with a bad idle air control valve?

Technically, you may be able to drive with a bad IAC—but you should not continue doing so. A bad IAC can potentially lead to stalling, which can compromise vehicle safety. Plus, you won't pass a state emissions test if the check engine light is on due to a bad IAC.

How do you clean the idle air control valve on a Toyota?

Spray the inside of the IAC valve with throttle body cleaner. Clean any carbon, dirt and debris using a wire brush and rag. Place the IAC valve back onto the mount and replace the two bolts that secure the valve in place. Use the socket wrench to tighten and secure the bolts.

How do I reset my idle air control valve?

Turn the ignition ON and leave on for several seconds then turn the ignition OFF to allow the ECM to reset the IAC valve. You should be good to go.

What happens if IAC is stuck open?

An obstructed or stuck-shut IAC will result in a rich air-fuel ratio at idle, so the engine will start very easily while cold and then die suddenly after a slight puff of black tail-pipe smoke. A stuck-open IAC might start fine while warm and may continue to run if the engine reaches high-enough RPM.