99 Silverado iac valve problem.
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CF Beginner
Joined: Sep 2018
Posts: 2
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99 Silverado iac valve problem.
Hello my name is joe I have a 99 Silverado with 192xxx miles 5.3l about a month or so ago it would have a idle issue to where when it would start it would jump to about 3000rpm then down to around say 100 or 200 then would idle back up at 700rpm I asked around town and came to the conclusion it’s the iac valve so I replaced it and reset it following the instructions in the package. It worked for a couple days perfectly fine until last night, I got off work and the truck was cold I went to start it and it started then died right away so I tried a couple more times with the same outcome the only way I could get it to idle was to hold the gas down to 1200rpm till it warmed up and it would idle but really rough does anyone have any ideas? I’ve done a lot of research and couldn’t find anything to go off of. New parts it has since this problem occurred fuel pressure regulator, Pcv valve, throttle body gasket, and I did the intake gaskets a couple months ago.
CF Monarch
Joined: Oct 2017
Posts: 4,605
Likes: 269
From: USA
Hello my name is joe I have a 99 Silverado with 192xxx miles 5.3l about a month or so ago it would have a idle issue to where when it would start it would jump to about 3000rpm then down to around say 100 or 200 then would idle back up at 700rpm I asked around town and came to the conclusion it’s the iac valve so I replaced it and reset it following the instructions in the package. It worked for a couple days perfectly fine until last night, I got off work and the truck was cold I went to start it and it started then died right away so I tried a couple more times with the same outcome the only way I could get it to idle was to hold the gas down to 1200rpm till it warmed up and it would idle but really rough does anyone have any ideas? I’ve done a lot of research and couldn’t find anything to go off of. New parts it has since this problem occurred fuel pressure regulator, Pcv valve, throttle body gasket, and I did the intake gaskets a couple months ago.