Engine quits randomly

BRIANEASTMAN

MEMBER
2005 GMC SIERRA
5.3L
V8
4WD
AUTOMATIC
109,000 MILES

My engine stalls randomly in all driving conditions. There are no lights or codes displayed. It will not restart. It will restart after siting overnight and run for a while then quit again randomly. The engine is only a few months old and only has 6,000 miles on it. I changed the fuel pump and cleaned the tank hoping that would fix the issue but that didn't fix it. The pump primes the manifold and appears to be running properly. The engine runs great with no other problems. Do you think it could be a crankshaft sensor or possibly a ground problem?

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3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon,

Thanks for the video.

The fact there is no tachometer signal cranking when it stalls out tells me the ECM is not seeing the crank sensor reading.

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works

I would start there and replace the sensor and make sure the connector is clean and tight.

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

The starter motor has to be removed to access the sensor.

When you are done, a sensor relearn must be performed using a real scan tool that can perform this procedure.

Roy

CRANKSHAFT POSITION (CKP) SENSOR REPLACEMENT

REMOVAL PROCEDURE

IMPORTANT: Perform the CKP System Variation Learn Procedure whenever the crankshaft position sensor is removed or replaced.

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1. Remove the starter.
2. Disconnect the crankshaft position (CKP) sensor electrical connector.

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3. Clean the area around the CKP sensor before removal in order to avoid debris from entering the engine.
4. Remove the CKP sensor bolt.
5. Remove the CKP sensor.

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