Saturday, August 25, 2012
Car care: troubleshooting engine starting problems
[Article copyright Ewe Paik Leong]
A man couldn't start his car after a few attempts. Without bothering to figure out why, he phoned for a mechanic. When the mechanic arrived, he found that the car's battery and engine were okay and that the car was merely out of petrol! This article will help you identify the possible causes of a starting problem and perhaps rectify the fault yourself.
Problem: You’ve parked your car in the rain for several hours and it won't start or you have just driven through a puddle and the car stops and can't get started. Possible causes are a bad distributor cap or spark plug wires, or your distributor cap has gotten wet.
Problem: It is early morning and cold outside. You haven't used your car for several hours and it can't start. The starter is okay and the starting noises are normal. Your problem could lie in the fuel injection system, or the choke on the carburetor (assuming you have one) is not closing, or some parts in the intake manifold system loose or broken.
Problem: You've just switched off the engine after having driven the car around. A short while later when the engine is still hot, you can't restart the car, but the starter is fine; so are the normal starting noises. Such a situation indicates a problem in the computerized engine control circuit or an overheated electronic part in the ignition system.
Another problem is when the starter works the engine over very slowly when the latter is warm. Typical situation might be this: having driven the car, you've switched off the engine. Later, when the engine is still warm, you try to re-start and can hear the starter working fine but it's slow. The engine does not start. You wait a little longer and find that the starter improves performance. The longer you wait, the better are the chances of starting. What's wrong? One possible fault is the battery which may be weak or its cables are already bad or some connections are loose. Also possible cause is engine oil that is too thin or contaminated with petrol. A third possibility is the starter itself, which might be overheated.
A fifth problem is when the car can't start after it has sat overnight. Normally, the scenario is as follows: you try to start your car but the battery seems either dead or weak. The starter clicks faintly or there is no starting noise at all. However, after you have jumped the battery, the car starts and runs normally. The next day, or after several hours when the car has sat, the problem recurs. Very likely, your battery is already weak. Also likely is a short circuit in your car. A final possibility is that something in the car was left on and stayed on even though the engine was turned off.
Our next problem does not concern the battery. The situation is this: The starter works without any problem. All the normal starting noises are heard but the engine will not growl into life. As you make more and more attempts to start, the starter slows down and begins to sound different. The cause is the battery being worn down. Look for the following possible causes: the petrol tank is empty; the petrol filter is clogged; the petrol pump has broken down; the carburetor has been over-flooded with petrol; something is faulty with the ignition system; the engine's timing belt is broken.
Problem: You have just turned the ignition key and the starter works fine: the engine is running. But when you release the key from the start position, the engine stops. You re-start and the engine jumps to life. But again the engine stops when you let go of the key to stop the starter. This condition can mean the ignition switch is faulty. It can also indicate a problem in the computerized engine control circuit. Last but not least, a resister wire in the ignition system could be bad.
Problem: The engine starts okay, runs for a few seconds, then it "commits suicide". You re-start the engine and it runs again. But it stops down again after a few seconds. This problem usually happens without any warning. Possible causes include: a faulty electric petrol pump shutting down after start-up, a fault in the computerized engine control circuit; a bad ignition switch, or a carburetor choke that is out of adjustment (if there is one).
Problem: The engine takes too long to start. Also, the car seems to be losing power over a period of time. The possible causes are many: (1) if there is a carburetor, the choke may be faulty, (2) the engine is suffering from mechanical problems, (3) the fuel pressure regulator is not operating at sufficient pressure, (4) the ignition timing is wrong, (5) something is faulty with the ignition system, or (6) the fuel injectors are leaking.
To round off the article, here are so noise-related symptoms: Problem: you turn the ignition key and hear a clicking noise then nothing. Funny, the car was okay yesterday (or a few hours ago). Probable faults include: (1) loose battery connections, (2) a weak battery, (3) bad battery cables, (4) starter relay is bad, (5) something is wrong with the charging system.
Problem: you turn the ignition key and don't hear anything. The following are the likely causes: (1) the battery has conked out, (2) the battery cables are bad, (3) something electrical was not switched off when the park was parked, (4) something is wrong with the charging system, or (5) something is faulty in the electrical system.
Problem: you turn the key and the starter grinds slowly but the engine starts. On consecutive starts, the starter turns even more slowly. You know a time will come when the engine will not start. Likely causes are: (1) a worn-out starter (2) a weak or dead battery, (3) dirty or bad battery cables, (4) engine oil that is too dirty.