Why Does My Car Take So Long To Start?

If you're like me you find it stressful and even a little embarrassing when your car takes a long time to start in the morning or after getting off work.

Why does my car take so long to start? A problem with the fuel, ignition or charging system can lead to a car taking a long time to start.

Below are some steps you can take to troubleshoot and hone in on the system and part that is causing the problem.

I have often wondered why a car could take a long time to start so I did some digging and came up with a list of reasons starting with the easiest problems leading up to the most difficult.

It is important to get a hard starting problem taken care of as oftentimes a vehicle taking a long time to start is an indication that a component is wearing out that may lead to an even worse problem and inconvenience down the road.

So it is critical that you diagnose and fix the problem as soon as possible.

There are various systems and components in the car that work together to start the vehicle.

We will explain the systems one at a time, along with troubleshooting tips, to help narrow down your hard-starting problem and offer solutions to keep your car reliable and safely on the road.

Diagnosing Using an OBDII Scanning Tool

First off, I highly recommend buying an OBDII scanner. An OBDII scanner will detect trouble codes that your car's ECU (electronic control unit) returns out.

AN OBDII scanner is compatible with all makes and models post 1996 sold in the USA.

Using an OBD2 scanner to get trouble codes
Using an OBD2 scanner to get trouble codes

Cheap reliable scanners are available for around $20.

They plug into your car's OBDII port and then connect to an app on your phone via bluetooth. Compatible with both IOS and Android.

Codes returned will oftentimes point directly to the charging, fuel or ignition systems making troubleshooting far easier, less time consuming and cheaper!

Whether or not you have a scanner you'll want to read through the rest of the article in its entirety to get familiar with the car's systems and how they could be causing your car to take a long time to start.

Charging System

First off we will have a look at the vehicle's charging system.

Overview Of Components Of A Vehicle's Charging System

The charging system consists of:

Mechanic charging a car battery
Mechanic charging a car battery

The Battery

  • Supplies energy to the starter which cranks the engine over to start it
  • Delivers smooth electricity to power electrical components in car

As a battery ages it loses its effectiveness as the chemicals inside get depleted.

Eventually as the battery wears out it will no longer be able to hold a charge large enough to start the car.

A poorly charged or worn-out battery can be a reason why your car takes a long time to start.

The battery will not have the juice to crank the starter over fast enough to develop the required momentum to start the engine.

If a battery is worn or depleted it is important to troubleshoot why! Is it just because its old? Or is it because a faulty alternator is not charging it properly?

Troubleshooting Routine:

  1. A simple way to check the battery is to turn the key over one click until your dash lights up but the starter doesn't engage and the car stays off.
  2. Read the voltage gauge and it should read about 12 Volts. If it reads less it means your battery is weak.
  3. Then turn the key one more click and start the engine. The voltage meter should now read 14 Volts. If it reads less it's a good indication that your alternator and or battery are failing.
  4. If you can't start the car have someone jump start the car and let it run.
  5. After it runs for a while, turn the car off then try to restart it.
  6. It points to a bad battery if the car doesn't restart as the alternator is providing a charge while the car is running but the battery is not holding that charge.

The Alternator

  • Keeps the car's battery charged
  • Works with the battery to deliver electricity to the cars electrical components

"An alternator works based on Faraday's Law which states that when a permanent magnet (alternator's rotor or coil) is moved (by the car's engine) relative to a conductor (alternator's stator), or vice versa, an electromotive force is created. If the wire is connected (alternator's stator) through an electrical load (car's electrical system), current will flow, and thus electrical energy is generated, converting the mechanical energy (car engine's ) of motion to electrical energy."

A bad or worn out belt may cause the belt that drives the alternator to slip which will lead to the alternator not spinning enough to fully charge the battery.

  • Check the belt for cracks or listen for belt squeal at the motor.

Bad diodes are a common cause of hard-starting. The alternator's diodes convert the alternator's AC current to DC current to charge the battery.

If one or two diodes fail you may still have enough power to charge the battery, but once a few more fail, the battery will not get fully charged.

Worn out brushes can cause a low charging situation.

Brushes provide a contact from the car's battery to the alternator's coil to control the alternator's voltage output.

A bad smell like burning rubber or hot wires can mean the alternator is overheating and it's time to replace it.

The Starter

  • An electric motor that gives the initial cranks to the car's engine to start it

First ensure there is voltage going to the starter! If no voltage is reaching the starter fix that first as the starter is probably not the problem!

If you are sure there is voltage going to the starter the following symptoms could be an indication of a bad starter:

  • No response when turning the ignition
  • The starter makes a clunking noise but does not engage with the motor
  • The starter turns but does not engage with the motor

If you turn the key and the engine turns over it's not a starter issue.

A faulty starter could have multiple causes:

  • Faulty electrical connections
    • Inside the starter there are electrical contacts that, when engaged, power the starter. Over time these contacts can wear out and provide less power to start the motor. Eventually you won't have enough power to turn the motor at which point you will need a new starter.
  • Faulty solenoid
  • Electrical motor damaged, perhaps from leaking oil
  • Gear pinion or freewheel damaged

The Wiring and Fasteners

  • Connect the various components of the car's electrical system

Look for melted wirings, disconnected connections, shorts, corrosion etc.

Bad wiring to the starter can cause a vehicle to take a long time to start or start inconsistently.

There are two wires that go to the starter:

  1. One thick line from the battery that supplies power to the starter to crank the motor over.
  2. A second smaller wire from the ignition switch in the car that detects when the key has been turned to activate the starter and crank the motor.

If one of these wires is damaged or if there is a poor connection in the circuit it can cause the vehicle to take a long time to start.

Bad wires or corroded terminals can prevent the battery from charging properly.

Inspect the wires for cracks and disconnect the fasteners from the battery and clean the terminals with a wire brush.

The Fuel System

If you have confirmed that you have a good battery, alternator and starter the next place to look is at the fuel system.

The fuel system consists of a pump, filter, regulator and injectors.

The pump pumps fuel through the filter and injectors and finally into the combustion chamber of the engine.

To diagnose the fuel system you can use a fuel line pressure gauge. Most fuel systems run between 35 and 45 psi.

  1. With the gauge tied into the fuel line and the ignition is turned to the first position without turning the car on. Pressure should build instantly.
  1. You then turn the key back to the off position and monitor the pressure over 10 minutes ensuring that pressure doesn't bleed off quickly. If pressure leaks off quickly, that could be a sign of a faulty regulator or a faulty check valve in the fuel pump.

Low fuel pressure can be the cause of hard starts because an insufficient amount of fuel is reaching the engine for combustion to occur.

This is called running lean. Low fuel pressure can be caused by a number of things including:

A clogged fuel filter - the fuel filter is located between the pump and the engine.

A plugged up fuel filter can prevent the necessary amount of fuel from getting to the injectors.

Faulty Fuel Regulator - A broken diaphragm spring in the fuel regulator can be the cause of low fuel pressure.

Diagnosing a Faulty Fuel Pump

  1. Check to see if you can hear the fuel pump running. Turn the key in the ignition 1 turn to the ACC setting to light up the dash but not start the motor.
  2. Listen near the gas cap and see if you can hear a buzz sound from the fuel pump.
  3. Next step if you don't hear the fuel pump running is to go under the hood and check the fuse for the fuel pump.
  4. There can also be a fuel pump relay in the fuse box. Have somebody turn the key on and see if you can hear the relay click.
  5. The next step is to hook up a fuel pressure gauge to the fuel rail and see what pressure we have that the fuel pump is producing. Turn on the key without starting the motor and monitor the pressure gauge. Healthy pressure is around 45-60psi. If you don't see any pressure or the pressure bleeds off rapidly, the problem could be a faulty fuel pump pressure. If you do see pressure and then it bleeds off there could be another leak in the system that you want to look for before you dig up the fuel pump from the gas tank.
Black car exhaust
Black car exhaust

Faulty Fuel Pressure Regulator

The fuel pressure regulator is the component that is responsible for regulating the pressure of the fuel that is pumped to the injectors.

Many regulators are vacuum powered as well some are electronically controlled.

If your car takes a long time to start plus one of the following symptoms is occurring you will want to dig in deeper and investigate your fuel pressure regulator.

There are a few common symptoms of a faulty regulator:

  • Black smoke coming from the exhaust
  • Black smoke coming from the exhaust almost certainly points to a bad fuel regulator. Black smoke coming from the exhaust is caused by too much fuel entering the combustion chamber or in other words the engine is running rich.
  • Gasoline dripping out of your exhaust pipe
  • Gasoline dripping out the exhaust pipe can be caused by a leaky fuel regulator leaking fuel through its vacuum line through to the intake manifold and again causing the engine to run rich.
  • Strong gas smell
  • Again a strong gas smell means the engine is running rich would most likely be caused by a faulty fuel pressure regulator.

Helpful Hint

A quick diagnostic technique is to disconnect the vacuum hose from the end of the fuel regulator and see if any fuel leaks out the regulator.

Leaking fuel points to a diaphragm leak and the regulator will need to be replaced.

Dead Or Clogged Injectors

  1. To diagnose an injector first you need a mechanics stethoscope or a long thin rubber hose will work.
  2. While the car is at idle place the stethoscope or hose up to each injector and listen for the injector tick.
  3. If you don't hear a tic noise you may have a faulty injector which can make a vehicle difficult to start.
  4. You may also get a check engine light with misfire codes on your OBD2 scanner.

To check for a clogged injector you need an injector tester. The tester simulates the injector system allowing you to diagnose each injector individually to find the clogged injector. You can then clean or replace the injector.

Ignition System

If your engine is flashing a check engine be sure to check that first! It may give you a misfire code pinpointing the exact cylinder that is misfiring, saving you a ton of time troubleshooting!

Ignition systems in modern vehicles can be complicated and are varied between vehicles but a commonality between all of them are the ignition coils and spark plugs.

A fouled spark plug has a harder time igniting the fuel in the engine which can be the cause of your vehicle taking a long time to start.

You can check if you have spark with a spark light test tool that is available at all automotive parts stores.

Modern cars use, via the crankshaft and camshaft position sensors, a computer to detect when spark should be delivered to the combustion chamber.

Why does my car take longer to start when it's cold?

A car can be difficult to start when cold for a few reasons.

One reason is that the cars computers need time to calibrate themselves.

  • When a car's engine is warmed up and running consistently, the computer knows exactly when to provide fuel and spark. During startup the computer may need a few moments to calibrate itself and figure out the proper spark and fuel timing.

The most obvious thing to do first is see if a check engine light is on.

If so you can use an OBD2 code reader to check your codes.

Google is your friend and you can google your code to find out if it is related to difficult starts and what components may be causing the problem.

Vacuum Leaks

A vacuum leak can lead to hard starts and/or rough idles.

To check for vacuum leaks you can first visually inspect and check for any cracked or disconnected hoses.

You can also use a smoke tool or carb cleaner to try for changes in idle.

Air Intake Tube

Air Intake Tube can be torn or cracked.

This can lead to additional air to enter the engine without the requisite increase in fuel which will lead to long crank times at start up.

Mass Airflow Sensor

The car's MAF (Mass Airflow Sensor) can cause a mixture issue due to contamination.

This can often be fixed by cleaning the MAF sensor with a can of MAF cleaner.

Anti-Theft System

A Problem with the car's anti-theft system could be the reason why the car won't start.

Some vehicles have an anti-theft system that consists of a chip in the key and a receiver inside the vehicle.

The key communicates with the receiver to let it know that it is the right key for the vehicle to start.


If your car is taking a long time to start it's important to find out why before it leads to bigger problems and maybe leaves you stranded.

An OBDII scanner tool is probably worth the investment as it can save you time and money in diagnosis.