Engine has a rough idle when started and there is a lightning bolt light illuminated on my dash that will not go off?

200,000 MILES • 5.7L • V8 • 2WD
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JOHN1OF1
  • MEMBER
  • 1 POST
I changed throttle body APS sensor, MAP sensor, and still getting rough idle when start.
Aug 7, 2023 at 11:46 AM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,246 POSTS
Hi,

Do you have control of the throttle or is it nonresponsive? Also, what codes are present? That can point me in the right direction to at least provide diagnostics specific to the potential problem.

As far as the rough idle is concerned, check to make sure no vacuum leaks are present. Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know.

Take care,

Joe
Aug 7, 2023 at 2:31 PM
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