# 1999 GMC Sierra 5.3 liter, Hard to start when engine is warm?

**URL:** <https://community.cartalk.com/t/1999-gmc-sierra-5-3-liter-hard-to-start-when-engine-is-warm/7126>\
**Category:** Maintenance/Repairs\
**Tags:** start, trucks, engines, gmc\
**Created:** [November 10, 2007, 7:57pm UTC](https://community.cartalk.com/t/1999-gmc-sierra-5-3-liter-hard-to-start-when-engine-is-warm/7126 "2007-11-10T19:57:58Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![america\_now](https://avatars.discourse-cdn.com/v4/letter/a/c68b51/32.png) [@america\_now](https://community.cartalk.com/u/america_now)\
**Post date:** [November 10, 2007, 7:57pm UTC](https://community.cartalk.com/t/1999-gmc-sierra-5-3-liter-hard-to-start-when-engine-is-warm/7126/1 "2007-11-10T19:57:58Z")

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Truck has 5.3 liter engine, just replaced spark plugs, and installed new oem fuel pump. Now, the fuel gauge works, but same  
  
 problem…Hard to start when engine is warm. Starts great when cold. Truck has about 90,000 mile. Help