Surging at idle

[MightyP]

Didn't get a chance this weekend to pull the TB off and clean it but that's my next step.

Regarding the couple suggestions that it could be a vacuum leak, it doesn't seem like there is a lot of vacuum lines on this engine so what are the likely locations?

 

[rbabody]

Under the throttle body there is a nipple that gets overlooked.

 

[MightyP]

Under the throttle body there is a nipple that gets overlooked.

Never overlook the nipple eh? That'll be easy to check when I pull it off for cleaning this weekend. I'm just hoping that I don't find out that the intake manifold gaskets are prone to leaking.

 

[oldcolt]

Never overlook the nipple eh? That'll be easy to check when I pull it off for cleaning this weekend. I'm just hoping that I don't find out that the intake manifold gaskets are prone to leaking.

The intake gaskets are reusable.....to a point. If in doubt. pick up a new set.

 

[MightyP]

Quick update, I just pulled the throttle body and cleaned it, everything seemed to in fine order, barely any soot buildup. The slow return to idle however continues. I'll have to do some checking for vacuum leaks next.

 

[Slitherbeast]

the tubing to the cruise control. the exhaust heats the plastic and it become brittle. plastic tubing may be cracked. The one that crossing the gap and goes under the battery tray.

 

[Engin89]

Check this as well......

 

[Cudawrestler]

I've noticed that on occasion I get some surging and high idle (1k) if I goose the throttle a bit and then come to a stop. It seems to last for a minute or more and then clears up.

It's an 05 QC with about 21k miles, stock motor AFAIK with exception of a K&N filter.

No engine codes or any other items going on but it's fairly reproducible and I'm pretty sure not a standard feature of the motor.

Anyone have any troubleshooting tips to start with?

Did you ever get it figured out?

Sent from my SM-G935T using Tapatalk

 

[Slitherbeast]

The BBK has a weak return spring....