Engine stalling

ACE WOODRUFF

MEMBER
1997 CHEVROLET 1500
300,000 MILES

Every now and then when I start my truck it will run for like three minutes then shuts off at idle or driving. It will restart and shuts off again, then has a hard time starting back up, but will finally start. Replaced fuel pump ran good for two days and did it again. I get no check engine light. I don't know what else it could be.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,133 POSTS

Welcome to 2CarPros.

When this happens, does it ever fail to start until it cools off? If so, when that happens, I need you to confirm fuel pressure and check for spark. Here are a couple links that may be helpful. I realize the pump is new, but there could be a blockage.

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

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Next, what you described sounds like an issue with the crankshaft position sensor. When they start going bad, they will internally short when they get hot. The result is no spark, which can shut down the engine. Interestingly, they don't always set a code. Take a look through these links. The second one describes symptoms of a bad sensor.

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

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

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

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I'm not sure what engine you have, so I went with the most common one, the 5.7L Here are the directions specific for sensor replacement. If you have a different engine, let me know. Also, the attached pictures correlate with the directions.

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.

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

Take care,
Joe

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