Truck doesn't like to start when the engine is warm

VIKESMAN69

MEMBER
1999 CHEVROLET SILVERADO
14,000 MILES

My truck doesnt like to start when the engine is warm, but will start with no problem when it is considered cold. It takes 3 or 4 cranks to get it started. I have replaced the fuel filter, spark plugs, and put some fuel injector cleaner in. I have had the battery checked and thats ok. I do have a cold air intake installed. Im pretty sure this is a fuel problem cause it sounds like it doesnt get the fuel it needs to start.

Tuesday, October 4th, 2011 AT 2:29 AM

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

It sounds like you might have a faulty crankshaft positing sensor.
The crankshaft position sensor sends signals to the PCM which triggers the engine to start.
Over time the crank sensor will start to loose its internal calibration due to heat and vibration of the engine.

When a crank sensor starts to fail, its performance gets impacted by temperature.
Typically hot engine will trigger it and it will not provide signal and the engine will not start.

You might find these articles helpful:

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

I have attached diagrams for your reference.

Please let me know of any questions.

Thank you.

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