Chevrolet Astro Parts And Chevrolet Astro Accessories
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Chevrolet Astro: Why It Misfires and Runs Roughly
Misfire is a common problem in Chevrolet Astro, and its diagnosis may not be as simple as you think, depending on the cause. When misfires occur, your Chevy\'s performance suffers along with fuel economy, emissions, and idle quality. And, when a misfiring vehicle is subjected to an emissions test, it will ordinarily fail because of the unusually high levels of hydrocarbons (HC) in the exhaust.
The common cause of a rough ride
When you\'re driving and notice any unwarranted rumbling, bouncing, shaking, swaying, rocking, wobbling, or other odd feelings while either in motion or attempting to stop, there might be a mechanical problem. A properly operating engine should run smoothly and without excessive noise. If the engine of your Chevrolet Astro starts operating in a way that gives you the perception of running rough, it is probably due to a handful of common causes such as engine misfire, vacuum leak, dirty fuel injectors, carburetor problems, and defective EGR valve, ignition coil, and spark plug wires. These parts should be checked thoroughly to rule out the unlikely causes.
The signs and symptoms
Engine misfire can be caused by a number of things and manifest itself through a number of symptoms. One symptom which manifests on the sound tells you how well your muffler is.you may be able to hear a misfire in one or more cylinders. As the affected cylinders come up in the rotation, the decibel level of the exhaust note on the misfiring cylinder will drop, followed by a full-volume report as the next cylinder fires. Second, when a cylinder misfires, it will discharge an unburned, or partially burned, fuel-air charge into the exhaust stream. This will manifest itself as a heavy gas smell in the exhaust. Third, misses can display certain symptoms in the exhaust stream, depending on the cause of the miss. Misses being caused by carbon fouling due to rich-running condition will have a puffy, black appearance.
The use of scan tool
What will a scan tool tell you about misfire? Not much, unless the vehicle is equipped with OBDII (1996 or newer). When the OBD II system detects a misfire that exceeds \"normal\" limits, it illuminates the Check Engine light and sets a P-code that corresponds to the misfiring cylinder. The last number in a P0300 series code tells you which cylinder is misfiring. A code P0304, for example, says cylinder number four is misfiring. If you also find a P0204 code (P0200 series codes cover the injectors), you\'d know the misfire was probably caused by a bad injector.
If you find a P0300 code, it only means the misfire is random and is moving around from cylinder to cylinder. The reason here would be something that upsets the engine\'s air/fuel mixture, such as a major vacuum leak, leaky EGR valve or unusually low fuel pressure (weak pump or faulty pressure regulator). There\'s really no magic bullet for finding misfires. It takes a certain amount of detective work to isolate the fault and determine the underlying cause. So, the next time you experience a misfire, don\'t miss the mark.