8 Causes and Fixes for When a Car Hesitates to Start

While usually a sign the vehicle needs to be tuned up, there are other causes that can occur.

A car needs the correct mixture of gas and air combined with a spark to start immediately.

If this combination of things is off, the vehicle will hesitate to start.

Long start times are usually easy to narrow down and fix, with some of the most common problems below.

8 Causes and Fixes for When a Car Hesitates to Start

• Fuel Pressure Regulator


The fuel pressure regulator is what holds the gas pressure in the fuel line.

If it fails to work, the gas will drain back into the gas tank and needs to be pumped back up again.

If the gas drains back into the tank, it can take a while to get the pressure back up and the car started again.

This is a common problem for long start times and, depending on the car, is usually an easy fix.

A quick way to test this is to cycle the key from on to off 4-5 times, wait 4-5 seconds in-between turns, and then start the car.

If the car starts immediately, the fuel pressure regulator has failed.

If it still has a long start time, it is likely something else.

This method works since the fuel pump turns on when the key is in the on position.

Cycling the key from on to off builds the pressure in the gas line up before starting the car.

When doing this, keep in mind a bad fuel filter can also cause the same symptoms.

• Fuel Filter


A fuel filter keeps debris from entering the fuel injection system, which would otherwise clog up the system.

The filter should be replaced regularly as part of standard maintenance.

If it becomes clogged up with debris, it will hinder the flow of gas into the engine and can cause long start times.

• Spark Plugs and Plug Wires


Spark plugs last a long time along with the plug wires but do need to be replaced as part of maintenance.

They are usually replaced every 30,000 miles but can last much longer.

If they are very old and the car has many miles on it they likely need to be replaced.

The spark plug wires should also be replaced at the same time as they have aged along with the spark plugs.

• Distributor Cap and Rotor


If your car uses a distributor ignition, it also needs to be replaced as part of regular maintenance along with the rotor.

They get worn with age and can stop sending out a good spark as they did when new.

• Dirty Air Filter


A dirty air filter will restrict the airflow going into an engine and is usually replaced every 12,000-15,000 miles.

Often a dirty air filter will allow some debris into the intake, which causes other problems such as a dirty throttle body or MAF senor.

• Dirty Throttle Body


The throttle body controls the airflow and gas mixture that goes into an engine.

Dirt can build up inside the unit that causes it to not work correctly.

Often it will just need to be cleaned up with a small brush and some throttle body cleaner.

• MAF Airflow Sensor


The MAF sensor measures the amount of air going into an engine which allows the onboard computer (ECM) to regulate the gas fuel ratio.

If it gets dirty or goes bad, the ECM will get bad information which causes issues with a vehicle.

The MAF sensor is located in the air intake and the first thing the air flows past after the air filter.

Often the sensor only needs to be cleaned and will start working again, but in some cases, it may have gone bad.

• Throttle Body Position Sensor


The throttle body position sensor is located on the throttle body and sends data to the onboard computer.

The computer then adjusts the air/fuel ratio the car needs to run.

If the sensor is bad, the vehicle computer will get bad data and not be able to get the air/fuel correct.

Summary
A car that hesitates to start has a problem that should be found and fixed.

Usually, the problem is not difficult to find and repair and many times is a part of regular maintenance.

If you regularly keep up the maintenance on your car, the first thing to check is the fuel pressure regulator.

The regulator is a common problem, especially when other things such as spark plugs and gas filter have been regularly replaced.

There are, of course, sometimes problems that are harder to find and can be car specific.

The above list is simply the most common problem that occurs when a car has a long crank time and hesitates to start.