5.3 idle issue 09 tahoe

[SKIDOO]

My 09 tahoe with a 5.3 has a higher idle when the outside air temp drops below approx 45 degrees. Summer it's fine. Idles about 750 in gear with foot on brake. But not all the time. Sometimes if you shut it off then restart it it idles normally. Had the throttle plate cleaned and relearned idle but this didn't help. Not sure what to try next. Sometimes its fine but sometimes it idles high. But it always has a consistent idle, either normal or high until you restart.

 

[ls1frc]

That's normal, they are designed to idle higher in colder temps it's right in the tune.

 

[SKIDOO]

That's normal, they are designed to idle higher in colder temps it's right in the tune.

 

[SKIDOO]

But then how come if i shut it off then restart it it idles lower, somtimes?

 

[Doubeleive]

try cleaning or replacing the maf, if you are at 160k or above it's probably time to replace the maf anyway. You really shouldn't have a higher idle unless it is really cold outside like below freezing and only for a few minutes until it warms up a little then it should kick down on it's own.

 

[SKIDOO]

I'll try that next. Thanks

 

[ls1frc]

Idle params

 

[ls1frc]

If it's doing it with coolant warmed up, then I'd check around for vacuum leaks