If your car starts then dies, it can be a stressful and frustrating problem. Whether the engine cuts out straight after starting the vehicle up or whether it dies after a couple of minutes, there are a few different components or systems that could be causing the failure.
It can be difficult to know where to start if your car is starting then dying. Knowing how to diagnose and investigate the problem is key, so you can begin to rectify it. Since there can be so many factors that come into play to determine the cause of your problem, the best way of starting a diagnostic is to work out, as far as possible, under which conditions the stalling takes place then focus on the components or systems that are associated with failing under those particular conditions.
Read on to get some expert insight into how to get started with this process.
Investigating and Diagnosing the Problem
Here are a few things that you might want to check to determine the cause of your car’s stalling problem.
Checking for Codes
The first step is to check your car’s computer system for DTCs (diagnostic trouble codes) stored inside its memory. You should do this whether or not the vehicle’s “check engine” light has lit up. Some of the sensors could have triggered a code. Should you not have an OBD2 scanning tool, a nearby auto parts store may be able to help you retrieve the codes or may be able to lend you a scanner. Alternatively, you could purchase a scanner of your own, so you could carry out the checks yourself for free.
Checking the Vehicle’s Anti-Theft System
Your vehicle’s anti-theft system could be causing the problem. This is especially likely to be the case if the relevant dashboard light has been blinking recently. Sometimes, all that is required to resolve your stalling problem is resetting the system so the engine begins to function properly again. The vehicle’s repair manual should show you how to do this.
The next step is to determine when the fault occurs and take the relevant steps outlined in the sections below.
My Engine Stops Immediately After Starting
If your car engine is stopping as soon as the key returns from start to run, this could indicate that the ignition switch needs adjustment, that there are burned or worn-out contacts, or that the fuel filter is badly clogged.
You can test quickly to determine whether the car’s fuel system is the source of the problem by using starting fluid or carburetor cleaner.
- Disconnect the throttle body carefully from the air cleaner outlet tube.
- Get someone to start up the car’s engine for you.
- When the engine has caught, and the key has returned to its Run position, you should spray the cleaner or starting fluid into the car’s throttle body.
Should the engine momentarily idle when the cleaner has been added, fuel delivery could be the source of the problem. The issue may lie with the fuel pump, fuel filter, fuel pressure regulator, or ballast resistor.
Begin by checking the car’s fuel filter. If it hasn’t been replaced recently, this could solve your problem. Take out the filter and blow through it in the same direction as the fuel would flow. If air won’t go through or only does so with difficulty, your problem has been identified.
If this isn’t the problem, check the system pressure with a fuel pressure gauge by following the instructions found in your vehicle’s repair manual.
There are several components that could be causing you trouble, including the:
- Fuel injectors
- Fuel pump
- CKP (crankshaft position) sensor
- ECT (engine coolant temperature) sensor
- Fuel pressure regulator
Typically, the CEL (check engine light) will be triggered if the CKP is bad. This is why scanning your onboard computer for any DTCs is so important.
While you’re cranking the car’s engine, watch the dashboard tachometer. If RPMs stay at 0, this could indicate the CKP sensor has a problem. Even when the CKP sensor has no problem, there may be an electrical short or open somewhere in the circuits.
If fuel supply seems good and the tests already carried out have yielded no clues, check the car’s ignition switch since the switch contacts will wear out eventually. Hold the car key forward in the start position as you crank the engine. It’s possible that the engine catches, but once the key has returned to Run, the engine will die. You will need to access the ignition switch and check that the electrical connector and switch are correctly connected. Squeeze the connector and hold it together manually when you start up the engine. If it starts up and idles while you’re holding the components together, the switch needs to be properly connected.
If you get no results from this test, there are a few more tests you can do. Check for coking and build-up on the throttle plate and body. If there is a build-up of carbon, the throttle valve cannot operate properly. If there is no free movement of the valve, rough idling will occur, and the car may stall, even with a fairly light build-up. Coking often results in the engine dying straight after starting up. Using carburetor cleaner will remove any carbon build-up from the throttle valve and bore when necessary.
My Engine Is Stalling at Idle
There are several sources of this problem, which will depend on the type or configuration of the engine. Here are some of the possibilities:
The Ignition System Has a Problem
If there is only a weak spark from the ignition, it may not reach the vehicle’s spark plugs. You should check the spark plug wires and the plugs themselves by removing them and checking them one at a time. Use a wire gauge to check the gap between the electrodes and compare the readings with the specifications in the manual. Check the color of the plugs, too – they should be grayish tan or brown in color if they are working correctly. Any other color could indicate issues with the ignition, fuel, or other mechanical components. If the plug is wet, this could indicate that excess fuel is getting to the cylinder, or oil is leaking into the car’s combustion chamber through a worn-out valve stem seal, cylinder, or rig. If your vehicle’s engine has a distributor, you should also check its cap for oil contamination, carbon traces, and cracks.
The Canister Vent Valve Is Bad
If this component fails, the engine may stall when idling or accelerating. Your car’s manual should show you how to test the valve in your model.
The PCV Valve Is Stuck
If this valve gets stuck in the open position, excess air will flow into the car’s intake manifold when idling or accelerating. This valve should be removed and shaken. If it doesn’t rattle, it’s probably stuck.
The TPS (Throttle Position Sensor) Is Bad
If the contact points on this unit have worn out and failed, the air-fuel ratio may be incorrect for your car’s needs. You can usually see if you have a bad TPS because a DTC will be triggered.
The IAC Valve Has Problems
If the IAC valve isn’t working properly, the air cannot bypass the throttle valve when idling or when the temperature is cold, resulting in stalling. This valve can be tested with a digital multimeter. Its reading should be 10 – 12 volts and 6 – 13 ohms if it is functioning properly. You should also check whether the IAC is blocked, as this too could cause a stalling problem. Check for a build-up of carbon in the housing and pintle and the O-ring and clean with some carburetor cleaning whenever necessary.
The ECT Sensor Is Bad
This can be tested with a digital multimeter then by comparing the readings with those in the repair manual.
The EGR Valve Is Stuck
EGR valves often get blocked due to carbon build-up. These deposits could also stop the valve closing so the engine stalls when idling. Check the valve and replace if necessary.
The Catalytic Converter Is Bad
This is especially likely if you can hear rattling, have low engine power, and can smell an odor like rotten eggs. Typically, catalytic converter problems will trigger the CEL.
My Engine Is Stalling at Idle if I Don’t Press the Accelerator
This problem could indicate an issue with the vehicle’s fuel system.
For engines with a TBI system (throttle body injection), you can check its function by popping open the hood and removing the entire air cleaner assembly to access the throttle body. Switch the key to On but avoid starting the engine. Examine the injector. If fuel is leaking, you must replace it. Alternatively, it may have a broken or worn-out return spring or valve. Dirt may also have caused the valve to get stuck in its open position. You should also use a fuel pressure gauge to check the car’s fuel system.
For engines with a multiport fuel injection system, it can be hard to check for leaks in the fuel injectors. Read your repair manual to check how to detach them if necessary.
The fuel pressure regulator could also be a problem. Check it by detaching its vacuum hose and inspector inside the hose and the port itself for any sign of fuel. If any gas can be found in either of the components, the fuel pressure regulator should be replaced.
In rare cases, stalling may be due to leaks inside the car’s fuel delivery system, most specifically, its fuel pump. Check for any wet spots or fuel odors around the tubing, fuel hoses, and fuel rail as well as around the connectors.
My Engine Starts, Then Stops Once It Is Warm
If this occurs, it could indicate issues with several components, including the:
- Ignition coil or module
- CKP sensor
- Fuel pump
- CMP sensor
Usually, it occurs if an electric “open” has occurred inside one of those components’ internal circuits. Heat can cause a wire or coil to expand and lose electrical contact, leaving you unable to start up the engine once more until the component has cooled down.
You can try to locate the component at fault by checking to see if there’s a spark when the engine has died by disconnecting a spark plug wire and placing it around 2” from the surface of a metal bracket or the engine. Take care to use insulated pliers to do this. Ask another person to crank up the engine and check for a spark being produced. If there isn’t one, or the wire has to be closer than ¼” to the ground to produce a spark, the fault is probably with the CMP, CKP, ignition coil, or module.
If a spark is produced, check to see whether the fuel system is losing pressure when the car stalls by using a fuel pressure gauge to check the engine when it is at idle. If it is, this indicates issues with either the fuel pump or one of the system’s components.
My Engine Is Stalling Intermittently
If this is happening under a range of different conditions, there are several components that could be at fault:
The CPS (Camshaft Position Sensor) Is Bad
Usually, the CEL will be triggered if the CPS is bad, but even if it doesn’t illuminate, it’s worth checking the car’s computer for any DTCs.
The Engine Is Misfiring
This is another reason an engine may stall. A misfire will make a popping sound, and the engine will vibrate or jerk. Difficulty starting the engine and increased consumption of fuel are also issues associated with this problem.
The Air Filter Is Blocked
It’s possible to remove your vehicle’s air filter for checking. It should trap dust and dirt from the air stream that flows into the car’s intake manifold. You should remove the filter from its housing and hold it against a good light source. If you can barely see any light (or no light at all) getting through the element of the filter, it is clogged up and stopping sufficient air from flowing into the engine. This is causing the stalling problem.
There Are Vacuum Leaks
If there is a vacuum leak, the actuators or sensors that depend on the vacuum for their operation may become upset. These include the MAP (manifold absolute pressure) sensor, the EGR (exhaust gas recirculation) valve, and the MAF (mass airflow) sensor. Leaks can occur due to damaged or loose gaskets or hoses. Check the vacuum hose itself as well as its electrical wires and connection before testing the actual sensor itself. You should check in your vehicle’s repair manual how to do this.
Check for dirt on the sensing element of your MAF sensor and clean it, if necessary, with an electrical contact or MAF sensor cleaner. Often, a vacuum leak will make a sound like hissing, but you may require a length of hose or mechanic’s stethoscope to listen for this sound and locate the leak. Make sure that all of the vacuum hoses have been properly connected and have no tears or damage. Use a length of hose or stethoscope to listen along the hose and its connections for a leak. Trace along each of the hoses manually to feel for any damage such as hard, soft or irregular patches.
Check too for any vacuum leaks which may have occurred around the throttle body and intake manifold gasket.
Diagnosing Your Engine Shut off Problem
If your car starts then dies, it’s important to diagnose the cause of the problem as quickly as possible. It isn’t always easy to determine the source of the issue, particularly if you lack experience with car repairs, as the problem could be due to a fault in one of a number of different systems or components. Luckily, this expert guide offers you some strategies to help you pinpoint the fault. You will be able to repair your own vehicle more quickly as you’ll be able to focus on the systems that are most likely to have caused the issue to arise in the first place. Simply follow the checklist outlined above, and you should have a coherent and systematic approach to help you determine why your engine is shutting off, whether it be immediately after starting up or once it has warmed up.
If you’re still struggling to work out why your engine is shutting off after starting up after following this expert advice, the best solution is to take your car to a professional mechanic who can diagnose the problem for you and carry out essential repairs so you can get your car back out on the road once more.
