At stoplight, idle increases 600 rpm when depressing clutch and no throttle peddle.

[JField]

We are traveling and just started experiencing the above mentioned issue. G56, 5.9, 200500 on
odometer. Stop at a traffic signal, while waiting for the light to change, step on clutch pedal and idle increases from 800 rpm to 1500 rpm with no accelerator pedal imput. Anyone have any ideas about what going on?

 

[NIsaacs]

Crack in the firewall? Clutch resistance deforms it slightly?

 

[Ozymandias]

Mine does it occasionally, a restart solves it for months to come.
I don't care for it as it is so seldom.

 

[Darkbloodmon]

We are traveling and just started experiencing the above mentioned issue. G56, 5.9, 200500 on
odometer. Stop at a traffic signal, while waiting for the light to change, step on clutch pedal and idle increases from 800 rpm to 1500 rpm with no accelerator pedal imput. Anyone have any ideas about what going on?

My 03 NV56 did something similar before I replaced my injectors, without throttle input at a stop RPMs would climb (I forget how high but relative to your description).

"Hanging Idle" is the commonly associated term of what your describing.

 

[AH64ID]

My 03 NV56 did something similar before I replaced my injectors, without throttle input at a stop RPMs would climb (I forget how high but relative to your description).

"Hanging Idle" is the commonly associated term of what your describing.

Hanging or hung idle is something slightly different, as it occurs after a throttle input.

This is likely caused by a failing injector, just as hung idle is thou.