Intermittent starting problem

2006 GMC YUKON

68,000 MILES • V8 • 4WD • AUTOMATIC

BOB AKERS

MEMBER
1 POST

Just recently about every 10th start the motor does not start immediately. It usually starts on the first crank. When it is slow to start it seems like either it is not getting fuel or it is not cranking quick enough. I guess my question is:
could it be the fuel pump
the starter
bad fuel

Aug 5, 2009 at 1:12 AM

SQM

✓Experienced Mechanic
6,383 POSTS

Hello,

It sounds like might be a sensor issue.
Could be a failing crank position sensor. That every once in a while, it malfunctions and does not allow the engine to start.

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

Is your check engine light illuminated? Sometimes with issues like this the light could get triggered. If it is illuminated, then retrieving the codes can help with the diagnostics.

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

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

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