The more complex a machine's construction, more complicated are the problems that arise in it. Cars being some of the most complex contraptions ever built, the problems that arise within them can be tough to diagnose. With modern cars having on board computer control systems and highly advanced technology operating within, the job of diagnosing car problems has become highly specialized. Still you don't need to bring in specialists at every instance of a car breakdown. There are still many things that you can figure out on your own.
The ignition system is responsible to get your car started. For the car to start working, the engine cycle that burns fuel to power the car ahead needs to be triggered. As you turn the key in car ignition switch, power is supplied to the starter motor. As soon as the motor gets activated, crankshaft starts turning, which moves the engine pistons into a compression stroke.
Consequently, as the pistons engage in the compression stroke, engine's inlet vent opens to introduce an air fuel mixture into the chamber and spark plugs produce a spark that ignites the compressed fuel, to begin the engine cycle. If any link in these chain of events goes wrong, the car doesn't start. With that background, let us see what could possibly go wrong, leading to a situation where a car engine turns but stops short of actually starting.
How to Diagnose a Car that Turns Over but Won't Start?
There are several things that could go wrong in the car's entire ignition mechanism. First up, check whether your car has enough gas. Sometimes, the reason for a car engine turning but not functioning is simply shortage of fuel! If you have checked that already, here are some of the other things you might want to check out.
Spark Plug Check
Since the car engine is turning, it means that the starter is working and therefore you can be assured that car battery isn't the problem. It is quite likely that the reason for starter failure is dysfunctional spark plugs. Get the spark plugs and connected wires checked and replaced if possible. That should solve your problem. Another reason for spark plugs not working might be flooding of fuel. In that case, you will have to get the plugs dried out, before they can function properly again.
Check Out Fuel Pump and Relay
Without fuel supplied at the right pressure, the engine cannot possibly start. If the spark plug check turns out to be fine, the problem might lie with the fuel pump and the relay that switches it on. Get both these devices checked and repaired if necessary to restore full engine functionality.
Timing Belt Check
A loose timing belt can cause a problem in the engine timing, which in turn may lead to a no starting problem. Open the car hood and check the tension of the timing belt. If it's old and cracked at places, it's best to get it replaced. Otherwise, get it tightened from a car repair professional.
Clean Air and Fuel Filters
A clogged fuel filter or air filter are some of the most common problems, causing a no starter problem. Remove both filters and clean them thoroughly. If they are too clogged out, it's best to get them replaced. That should get your engine back to its working ways.
So these were some of the possible causes that may lead to a situation where your car turns over but doesn't start. In most cases, the problem lies with the fuel pump, air filters or the spark plug. Despite checking out for all the above causes, if you still cannot diagnose the reason for your car's failure to start, it's best to bring in professionals, as the problem might be more complex. Regular maintenance checks and car servicing can prevent such no starter situation from cropping up in the future.