Engine stalls at idle?

Okay, I would check the actual fuel pressure to be sure you have correct fuel to the injectors.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Measure with the Key On Engine Off with the fuel pump commanded ON.

Vin (V,T,U)
Fuel Pressure (gasoline) .................... 55-62 psi

Vin (Z)
Fuel Pressure (ethanol) .................... 48-54 psi

These specifications are taken from the Fuel System Diagnosis. For complete testing of fuel pressures and volume see Fuel System Diagnosis, See: Computers and Control Systems > Testing and Inspection

The coolant sensor may also be an issue. If the reading are wrong, it will effect cold operation.

https://www.2carpros.com/articles/how-a-coolant-temperature-sensor-works

https://www.2carpros.com/articles/symptoms-of-a-bad-coolant-temperature-sensor

Roy

ENGINE COOLANT TEMPERATURE (ECT) SENSOR REPLACEMENT

REMOVAL PROCEDURE

NOTE: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

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1. Drain the cooling system until below the level of the engine coolant temperature (ECT) sensor. Refer to Draining and Filling Cooling System in Cooling System.
2. Disconnect the ECT sensor (1) electrical connector.

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3. Remove the ECT sensor.

INSTALLATION PROCEDURE

NOTE:
Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.
Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

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1. If installing the old sensor, coat the threads with sealant GM IP/N 12346004 (Canadian IP/N 10953480) or equivalent.

NOTE: Refer to Fastener Notice in Service Precautions.

2. Install the ECT sensor.

Tighten
Tighten the sensor to 20 N.m (15 lb ft).

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3. Connect the ECT sensor (1) electrical connector.
4. Fill the cooling system. Refer to Draining and Filling Cooling System in Cooling System.

Scan it to see if it's storing any codes here is a guide. Let me know what the codes are. But, also listen to it very closely under the hood. Often times you can hear a vacuum leak. A hose could have come unhooked, or split in half, that could easily cause what you are experiencing.

https://www.2carpros.com/articles/stall-at-idle

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Could be other things, but let me know what you get from the scan. Thanks!

Check and see if the fuel pressure regulator is blown. Located on the drivers side of the engine on the fuel rail, it has a vacuum line that goes up to the intake manifold. If there is fuel present in line replace the regulator. Check it after it starts and dies. Also clean out the throttle bore around the butterfly with carb cleaner and a rag, this will also help stabilize the idle

Hi and thanks for using 2CarPros.

This can be the result of a few different things. However, I first suspect a fuel pressure issue unless the check engine light is staying on. First, take a look through this link. It discusses the most common causes of an engine to stall at idle, what to check, and how to fix. Also, here is a link that shows how to check fuel pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

and

https://www.2carpros.com/articles/stall-at-idle

If that doesn't help, I suggest scanning the computer to see if there are any diagnostic trouble codes stored in the system. Here is a quick video showing how it is done:

https://youtu.be/YV3TRZwer8k

I realize most people don't own a scanner, but often times a parts store will lend or rent one to you.

Next, a bad crankshaft position can act this way, too. Take a look through this link. It discusses common symptoms and the second link shows in general how one is replaced.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

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Here are specific directions for replacing the crankshaft position sensor on your vehicle. The attached pictures correlate with these directions.

CRANKSHAFT POSITION SENSOR REPLACEMENT

picture 1

picture 2

picture 3

IMPORTANT: The CKP System System Variation Learning Procedure will need to be performed whenever the Crankshaft Position (CKP) sensor is removed or replaced. Refer to CKP System Variation Learn Procedure.

REMOVAL PROCEDURE
1. Remove the electrical connector.
2. Remove the sensor hold down bolt.
3. Remove the sensor from the timing cover.

NOTE: When installing or removing a crankshaft position (CKP) sensor make sure the sensor is fully seated and held stationary in the front cover before torquing the hold down bolt into the front cover. A sensor which is not seated may result in erratic operation and lead to the setting of false codes.

4. Inspect the sensor O-ring for wear, cracks or leakage. Replace if necessary. Lube the new O-ring with clean engine oil before installing.

INSTALLATION PROCEDURE

NOTE: Make certain that the Crankshaft Position (CKP) sensor mounting surfaces are clean and free of burrs before installing the CKP sensor.

1. Install the sensor into the timing cover.
2. Install the sensor hold down bolt.

Tighten
Tighten the hold down bolt to 8 Nm (71 lb in).

3. Install the electrical connector.
4. Perform the CKP System Variation Learn Procedure. Refer to CKP System Variation Learn Procedure.
____________________________

Crankshaft Position System Variation Learn

1. Install the scan tool.
2. Apply the vehicle's parking brake.
3. Block the drive wheels.
4. Close the hood.
5. Place the vehicle's transmission in Park (AT) or Neutral (MT).
6. Idle the engine until the coolant temperature reaches 65 C (150 F).
7. Turn OFF all the accessories.

Important:If the CKP System Variation Learn Procedure cannot be completed successfully, refer to DTC P1336 Crankshaft Position (CKP) System Variation Not Learned for additional diagnostic information. See: A L L Diagnostic Trouble Codes ( DTC ) > P Code Charts

8. Enable the Crankshaft Position System Variation Learn Procedure with the scan tool.

Important:After the ignition switch is turned to the CRANK position, the VCM must see a change in the state of brake switch (Released to Applied) to run the learn procedure. Also, the service brakes and the parking brake must be held throughout the duration of the learn procedure.

9. Apply and hold the service brakes.

Important:While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine will respond to throttle position after the learn procedure is complete.

10. Slowly raise the engine speed to 4,000 RPM.
11. Immediately release the throttle when the engine speed decreases.
12. Turn OFF the ignition for 15 seconds after the learn procedure is completed successfully.

______________________________________________________

If you decide to check the fuel pressure, here are the manufacturer's specs for pressure:

FUEL PRESSURE SPECIFICATIONS
Ignition On, Engine Off .................... 415 - 455 kPa (60 - 66 psi)

For additional fuel pressure testing and specifications, refer to Fuel System Diagnosis. See: Fuel Pressure > Component Tests and General Diagnostics > Fuel System Pressure Test

Let me know if this helps or if you have other questions.

Take care,
Joe

It sounds like a bad throttle position sensor or idle air control valve. Without a code, it a guess. Have you checked closely for vacuum leaks and intake leaks?

Was the year make and model the same?

If there is no check engine light, I bet there is an intake leak.

With the engine running, spray starting fluid, carb cleaner. Around the intake. If there is a leak, the engine will rev up.

Note: when doing this, you are spraying a very flammable product on a hot engine. A fire can start if you hit something like an exhaust manifold. Keep a fire extinguisher near.

Let me know what you find, and be careful.

If the vehicle starts then shuts off, one thought is the security system, pass-lock, fuel disable? thee guides can help su fix it

https://www.2carpros.com/articles/engine-stalls

and

https://www.2carpros.com/articles/how-to-reset-a-security-system

Please run down these guides and report back.