Why is my Ford Mustang running rough at idle?

Why is my Ford Mustang running rough at idle?

Really, your Mustang will be running rougher at any RPM, but a misfire will be most pronounced at idle. Spark Plug Wires – While not every model and engine combination of vehicles today comes with spark plug wires (a lot are now coil on plug), if your Mustang happens to have them, they can go bad and cause a rough idle.

Why does my Ford Mustang burble when I downshift?

The engine is recieving too much air through the IAC valve. From my knowledge Ford did this for emissions reasons. As a side effect of this fix, when you downshift, the car burbles a lot more, sounds like a carburated engine. You get a little more engine braking effect. Most older mustangs have an external IAC valve.

What to do if your Ford engine is running at idle?

Hook up a portable trouble code tool for your specific Ford make and model. Look for any trouble codes that appear while the engine runs at idle. Write down any code number and look it up in a trouble-code manual. Most times, code numbers can pinpoint the exact system failure or miss in the engine.

What causes a car to stall while idling?

A common problem with air passages in the throttle, and the IAC valve itself, is carbon, dirt or fuel varnish buildup. If air can’t go through the air ports when needed, the engine may stall when you reach a stop or while the engine is idling. Locate the IAC around the throttle body. Unplug the IAC solenoid electrical connector.

What causes idle problems in a Ford Mustang?

In this age of fuel injection, idle problems can literally be caused by hundreds of different things. What this series of articles is aimed at is how to fix the most common idle problems found in the Mustang. The fuel injected Mustang uses a small motor/valve assembly that allows a specific amount of air to enter the engine to control it’s idle.

The engine is recieving too much air through the IAC valve. From my knowledge Ford did this for emissions reasons. As a side effect of this fix, when you downshift, the car burbles a lot more, sounds like a carburated engine. You get a little more engine braking effect. Most older mustangs have an external IAC valve.

A common problem with air passages in the throttle, and the IAC valve itself, is carbon, dirt or fuel varnish buildup. If air can’t go through the air ports when needed, the engine may stall when you reach a stop or while the engine is idling. Locate the IAC around the throttle body. Unplug the IAC solenoid electrical connector.

How does the fuel injected Mustang engine work?

The fuel injected Mustang uses a small motor/valve assembly that allows a specific amount of air to enter the engine to control it’s idle. This valve is comonly called the idle motor, the IAC (idle air control) or the IAB (Idle air bypass). When your car is new the IAC works remarkably well.