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Car Stalling Problems

What would cause engine to idle rough and die when car slows down or stops?

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Wiki User
2007-06-09 19:17:41

It depends on what kind of car you have. Three things are needed

to "make fire" in the engine: fuel, air, and spark. If any of these

is interupted then it can sputter or just not run. How those three

gets there depends on the car. Older, carbureted engines mixed fuel

and air in the carburetor and then moved them into the piston. Fuel

interuptions would happen at the carburetor. Air interuptions

rarely happened, but could be because of poor settings inside the

carburetor. In newer engines the air and fuel are brought in

separately. A sticky fuel injector, low fuel pressure, or a

computer problem can cause rough idling. How the "spark" gets into

the cylinder, via spark plug, has not changed much. What triggers

the spark has. In older cars it could be a mechanical

distributor/rotor/points system. If there were debris in there, or

even poor spacing then the engine could rough-idle. In the newer

systems its all computer controlled or hybrid. It could have a weak

or discharged battery. It could have a weak alternator/generator.

It could have a clogged air or fuel filter. There are a lot of

things it can be. A quick inspection can tell a qualified mechanic

what the problem is. How he goes about determining what the problem

is and how to fix it really depends on the type of Car.


It could be something as simple as a fuel filter! Try that.

Then spark plugs and wires. Air filter.


If those check out fine or you have replaced them. Check for stored

trouble codes or an illuminated CEL.


It could also be a Idle Air Controller problem, if they get dirty

they can stick. Also, on computerized cars, crank and cam angle

sensors can go bad. Lots of things here.


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