Car cranks but wont start

changed battery ..car wont start

My car has 93000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
You did not list a vehicle in your question so this answer is general in nature. There have been many complaints when the batteries are replaced and then the vehicle will crank and no start due to the theft system becomes active. Sometimes all you have to do is remove your key, lock all your doors and close the hood and then wait ten to thirty minutes and then unlocking the door using the key and not the remote and then see if the vehicle starts normally.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

If the car cranks when you turn the key, but the engine won`t start, it could be because fuel isn`t getting to the engine. One potential reason for this could be dirty fuel injectors. Over time, the fuel injector nozzles can become clogged with rust, corrosion or debris.
Check the battery if your automobile with an anti-theft system won`t start. It may be completely depleted or low and require charging. Unfortunately, the car`s system won`t be able to read the key fob`s security code in that instance. Next, verify the battery`s connection.
Turn the key backward two places to the Lock position, then wait three more minutes. When that has elapsed, try to start the car. There`s often a fuse associated with the immobilizer, and like all fuses, it can blow. Check the owner`s manual to locate the fuse and assess its condition.
The engine won`t turn over. The most common signal that your starter has a problem is if nothing happens when you turn the key or push to start. Unusual noises, such as clinking, grinding and whirring. If you ignore these sounds, it can eventually lead to damage to the engine flywheel.
Immobiliser or security system

Sometimes, it`s your car`s own security system that stops the engine from starting – if the immobiliser fails to recognise your key, then your engine won`t start at all. This may be a flat battery in the key fob which weakens the signal from the fob to the system.

Passive anti-theft systems

Passive anti-theft devices include: An alarm system that activates automatically when you turn the ignition off or shut your car door. Automatic disabling devices such as a computer chip in the ignition key. This device will prevent the car from starting if an unrecognized key is used.

If your ECU controls the anti-theft system, disconnecting the battery may lock you out of your car. Like desktop computers and most other electronics, disconnecting the battery cable for a short period will not fully reset your ECU due to the residual power remaining in the circuits.
It is usually located on the dashboard by the driver`s door, in front of your left knee. You may find the alarm fuse in this fuse box. If you do not find an alarm fuse inside of the car, look in the fuse box under the hood on the driver`s side.
The vehicle must be armed electronically to enable the alarm system) Vehicle theft: This alert occurs when tampering is detected with the vehicle`s key cylinder. This can be triggered by an invalid key, screwdriver, foreign key fob or no key detected when trying to start the vehicle.
on January 15, 2016

How do I activate the immobilizer system? The immobilizer system keeps your vehicle from being turned on with an invalid key. When the immobilizer system is activated, only a valid key can be used with the car. The system will automatically active when the ignition is turned off.

Most modern immobilisers have a transponder embedded in the car`s key fob that transmits a code to the ECU whenever you insert the key into the ignition barrel.
Faulty Fuse

And if that`s faulty or the fusible links are damaged, your car wont start. A damaged or blown fuse can prevent power from reaching the starter relay, which is needed to provide the spark, the ignition, and the power to move your vehicle.

Signs of a Bad Starter

Turning the keys in the ignition won`t start the vehicle, but the dash lights come on. When jump starting your vehicle, it does not turn over at all. The vehicle cranks slowly or may even turn over weakly.

Starters Can Fail Due To Low Battery voltage

Typically what happens is the excess current created as a result of the low voltage causes the contact within the solenoid to weld together or even burn through.

CAUSES OF FAULTY STARTERS: CAUSE OF FAILURE

Electrical connections faulty. Solenoid switch (engaging relay) stiff or faulty. Electric motor damaged electrically. Single-pinion gear, starter pinion or freewheel damaged.

A ghost immobiliser includes systems that prevent key cloning, signal jamming and device spoofing – all methods that thieves use to unlock cars with standard immobilisers. This means that even if a thief is able to somehow get into your car, they won`t be able to drive it away.
The system prevents someone from starting the engine with an incorrectly coded key. When you switch the ignition off the engine immobilizer will arm automatically after a short time.
The auto immobilizer is the king of the passive systems. The immobilizer cuts off current to the starter motor, the ignition switch and the fuel pump.
The Anti-theft Light in the dash of your car should flash periodically to show that the system is engaged and active. You have to lock the doors of the car (without it running) for the alarm to engage.
Check the battery

The first thing you should take a look into when the anti theft system car wont start is the car battery. It could be dead or low and needs charging. In that case, the car`s system won`t be able to read the security code off the key fob.

Long Duration Settings – In most cases, your motion detector light should only stay on for 20 to 30 seconds after it`s triggered. However, you can manipulate the settings so it will stay on longer. For example, many lights come with settings ranging from a few seconds to an hour or more.
A metal shield that locks around your steering column, which prevents tampering with the ignition switch or starting mechanism. This prevents “hot-wiring” a car because the area is inaccessible.
When an engine cranks for a long time before it starts, either spark or fuel is missing or weak and each has its own reasons. Most of the time, the air / fuel mixture has been disturbed and there is too much air or not enough fuel.
When an engine cranks for a long time before it starts, either spark or fuel is missing or weak and each has its own reasons. Most of the time, the air / fuel mixture has been disturbed and there is too much air or not enough fuel.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My car will not start Intermittently. I purchased a new battery 2 weeks ago and yesterday the car wouldn’t start. Got a jump and
ANSWER : The issue you are having is probably due to an intermittent fault in the starter motor itself or a deficiency in the starter electrical circuit, for example a large voltage drop due to a poor ground or a high resistance connection. These issues can be readily diagnosed and resolved on a mobile basis if you request a hard starting diagnostic. If you request that diagnostic, the responding certified mechanic will get this resolved for you promptly. Based on Toyota’s Factory Service Manual, the battery should not be disconnected if the vehicle engine is running. The battery acts as a large resistive voltage sink and consequently taking the battery out of the circuit, while the alternator is still running, can create a voltage spike on the car’s electrical system which is not good for voltage sensitive components such as the engine computer. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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Why does my car start one day and the next day it wont start? The car will crank but wont turn over
ANSWER : Hello, thank you for writing in. With intermittent symptoms, diagnosis can take longer but is typically the same as diagnosing any other starting problem. The main issue is that you can only perform the testing needed when the issue is occurring. If the vehicle starts and works normally, all of the components are likely going to pass their tests. There are several components that will work intermittently. They include the fuel pump, charging system, a number of sensors, and any electrical connection that is loose. When the vehicle is not starting, test for fuel pressure, spark, and the electrical connection on any of the sensors that effects starting (air intake, camshaft/crankshaft position sensors). For more diagnostic help, contact our service department to schedule an appointment.

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The car is having trouble starting up ,70 percent of the time it starts right up. the other 30 percent, it randomly won’t start its
ANSWER : Hey there thanks for writing in about your 1998 Honda Accord. This could be a few things. A faulty ignition switch, a failing crank sensor, or possibly other faulty sensors could be the cause. To have this taken care of, consider having a certified technician, such as one from YourMechanic, come to your car’s location to diagnose and repair the hard start issue.

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When I go to crank my car the key stays in the start position and the car is constantly trying to crank itself.
ANSWER : First, let’s make sure about some terminology before I proceed. I will assume the motor is actually turning over. If the car is trying to start, the motor has to be turning over or it is not trying to start. This is an important distinction when diagnosing the starting system. As a technician, I go to different parts of the system based on this description.

If the key is stuck in the start position, this is a ignition lock cylinder issue and the reason the starter continues to turn the motor over. If the starter is turning but the motor is not, then the starter is likely the problem. Either that or the teeth on the flex plate are all gone. This would require removing the transmission to repair.

If the car runs intermittently, this can be a big challenge. And it also means the starting system is working. It will need to be diagnosed when it is failing. A working car cannot be diagnosed because there is nothing wrong. Where you park your car should not have any affect. It certainly could be a wiring problem. Wiring problems hide really well and can happen anywhere in the miles of wires that are in your car. Isolating the system that is failing is really important here. At the moment I am unsure which system is failing. Starter system, ignition lock cylinder and or ignition switch electrical or something with the engine control system.

When the car is failing, you need to check for spark and fuel pressure. If neither is present, this is a clue. Usually the crank sensor will do this. Does your car have a tachometer? If so, does it move at all when cranking. This is a clue whether or not the cam and or crank sensor is working. Is there a Check Engine Light on with the key on? If there is a Check Engine Light, the code or codes can be used for specific diagnosis.

All of these concerns will send you down a diagnostic path. Be sure not to confuse yourself by misinterpreting multiple system failures. If the key does stick in the start position, this would be the first problem to solve. After that, does the motor actually turn when the starter turns? After that, the question of "Why won’t it start?" is first answered by finding what the motor is lacking. Fuel, spark etc… Good luck.

If you need assistance with these checks, contact a certified mechanic who has the tools and experience needed to properly diagnose this starting issue with your car.

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Ok my car will not start it had the same issue a week ago I changed the cam and crank sensors. It cranks but wont start …HELP!
ANSWER : Prior to performing diagnostics be sure you have a fully charged battery that passes a load test. Then, confirm that the engine immobilizer system (security system) is not activated thus preventing the car from starting. To temporarily override the immobilizer system, see these instructions.

Be sure there is adequate fuel in the fuel tank and that the fuel is not old. Check for adequate fuel pressure, injector operation, and a spark at the spark plugs. Basically, if the starter motor is turning the engine over rapidly, at sufficient RPM, but the engine does not catch and run, that means that there is an ignition, fuel, air induction, or mechanical fault in the engine that will have to be repaired. Strictly speaking, you should first check engine compression in the cylinders because if there is no, or inadequate, compression the engine won’t run under any circumstances. If compression is found to be within factory specifications, and there is fresh fuel being delivered by the injectors (not just "to" the injectors) and the ignition system is working, that means that the air fuel ratio of the mixture delivered to the cylinders is so far off that the mixture just won’t ignite. Such could be due to a big vacuum leak, an air induction fault like a stuck idle air control valve or, considering fuel, could be due to a failed temperature sensor that must be working properly to signal the PCM to enrich the mixture on cold start. Other common faults are defective spark plugs or a defective coil. Regardless of the underlying cause, if you request a no start diagnostic the responding certified mechanic will get the problem diagnosed and repaired for you promptly. Please let us know if you have further concerns or questions as we are always here to help you.

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Map sensor car won’t start up good ?
ANSWER : Your MAP sensor is an important input for your computer. It helps determine the load on the engine to calculate the correct amount of fuel to inject. It sometimes takes a few seconds for the vehicle to realize that the sensor is not producing a good signal.

At that point, it will use other methods to determine the fuel rate, such as pre-programmed fuel maps, throttle position, etc. I would suggest replacing the MAP sensor and retesting. If you would like to have it checked first, a certified technician from YourMechanic will be able to scan your vehicle and test components to determine the root cause of your starting issue before making a repair.

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Car won’t crank when it’s cold and now won’t start at all
ANSWER : Hi there:

Usually this issue is cased by low cranking amps inside the battery. If you’ve recently had the battery replaced, it’s possible that an electrical component that makes up the charging system might be damaged or faulty. It’s also quite possible that the main electrical relay or the starter relay is giving you fits. To know for certain what the exact issue might be on your 1989 Toyota Camry, you should have a professional mobile mechanic complete a car is hard to start inspection, so they can pinpoint the source of your issues and recommend the right repairs.

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Fuel pump engages. Batery good, alternator good volts, jump start helps when wont start. Temp does not matter. Intermittent?
ANSWER : Hello. Thank you for writing in. There are several reasons your vehicle may only start when jump starting. The first and most common is a build up of resistance that is causing you to need a boost of voltage to get the engine started. This may be due to poor battery cables, a bad ground connection, a poor starter solenoid, and a couple of other issues. The first thing you want to do is perform a visual inspection of the starting system. Make sure there is no corrosion build up in the battery cables. You can also check the resistance across these wires and make sure you have a solid connection between components. You then want to make sure the starter solenoid is doing its job. It is responsible for taking the small amount of electricity sent by the ignition and turning it into a huge electrical charge that is strong enough to push over the engine with the help of some gear ratios in its favor. Do some more testing, and stick to the basics before assuming its something seriously complicated.

Read Full Q/A … : Car cranks but wont start