5 Causes When Car Starts Then Sputters and Shuts Off

If you have a vehicle and the engine starts but then sputters and shuts off, there can be several causes and fixes.

To narrow down troubleshot and find the problem, the best thing to do first is to read any error codes on the ECM/PCM with an OBDII scan tool.

This will help to narrow down the problem and not swap out unnecessary parts.

Step #1: Read The Onboard Computer for Any Error Codes

The first thing to do is to read the onboard computer ECM/PCM for any error codes.

Reading for engine error codes is quick and easy to do with many low cost OBDII scan tools available.

An engine error code will point to the failed component and the issue the engine is having.

For example, a P0101 code is a Mass Airflow (MAF) Circuit Operating Range or Performance Problem error.

This code would point to the MAF sensor as being dirty or having failed.

In this scenario cleaning or replacing the MAF sensor would likely solve the issue.

There are many low cost OBDII scan tools some for $20-$30 dollars.

An engine needs to have good timing, spark, and Fuel Air ratio correct to run good.

If any of these systems are having an issue the engine will run badly.

When an engine runs for roughly 1-minute, the spark and timing are usually good.

While there can be exceptions, an engine usually will not start if there is no spark or the timing is off.

So when an engine is starting, running a short while, and then shutting off there likely is an Air Fuel Ratio problem.

A bad or dirty MAF (Mass Ari Flow) sensor can cause issues.

The MAF sensor reports all the air that goes into an engine and when it malfunctions the Air Fuel ratio can be off.

This is a common issue with an OBDII scan tool giving codes such as P0101, P0102, P0103 and more.

A MAF sensor issue is an easy fix that is usually solved by cleaning or replacing it.

A clogged fuel filter will block the fuel going to the engine and cause issues.

This is mainly with inline fuel filters located under the vehicle along the frame.

Some vehicles have the fuel filter in the gas tank but many have the filter under the vehicle.

If your car has an inline fuel filter it is best to replace it as it is a part of regular maintenance.

A bad fuel pump will cause issues which can vary depending how badly it has failed.

A fuel pump usually does not pump at all when bad, but can sometimes pump but at a lower pressure.

If the fuel pressure is low the engine will not run correctly.

A fuel pressure test can be done which will show if the fuel pressure is low.

A vacuum leak, mainly with the intake manifold, can cause the Air Fuel ratio to be off.

There are different methods to test for a vacuum leak such as using a liquid spray to spray at a location and see if the engine idles up.

The best method, in my opinion, is to use a smoke machine that feeds smoke into the manifold and comes out at any leak point.

A bad fuel injector can cause many issues including the engine running badly.

The injector can be tested to see if one has failed.

When an injector does fail it will usually give another OBDII code, so be sure to look for any other OBDII error codes.