There can be a few reasons, mostly to do with the ignition. Possibly a plug is not firing, possibly one or two plug leads have been swapped inadvertently, possibly a valve is sticking.
Idle speed is not adjustable on this car.
No, that has nothing to do with idle speed.
the engine runs at a faster rate than when the idle speed is lower.
Idle speed control
Yes, There is a screw on the carburetor or throttle-body that controls idle speed.
Idle speed is automaticaly controlled by the computer. If idle speed is not correct, the car has a vacuum leak or a sensor problem.
The dodge neon has an optimum idle speed like any other car. The Dodge Neon's optimum idle speed at rest is between 12.9% and 13.3%.
The Renault Megane is a type of car popular in Europe and Australia. The average idle speed is around 750 RPM.
That doesn't make any sense. But if your car vibrates at idle and stand still, then you probably have a fuel delivery or ignition problem that is causing a misfire.
Hey Jonathan==It varries between cars. If your car is later than about 1986 it is computer controled and you cannot change it. Sometimes if the idle speed solonoid is bad or dirty, the idle will be wrong. Goodluck, Joe A vacuum leak will also cause idle quality issues.
An engine usually has a higher idle speed when the ac is running. If the high speed idle does not operate then the ac will cause the engine to stall.
The idle speed on modern computer controlled vehicles is not adjustable. If you are having idle problems you will need to take the car to a mechanic.