dropping idle

[shifty biscuits]

hey all. one of my new issues that has recently occurred is a dropping idle/stall problem when warm and clutch pedal is depressed. it started a few weeks back, when the car gets up to temp in any driving condition it will threaten to or actually cut out when the clutch is pressed to brake or shift down. (any time the clutch is down longer than an upshift)
the times it does not cut out the revs will dip low then return to a steady healthy rpm.
hot start is fine as is the idle hot or cold otherwise.

the car has very minor mods, exhaust (small bore) dump valve, ali rad, ht leads and thats about it, otherwise even stock down to the air box.

im just after some suggestions anyone may have to put on the list to check through..
cheers.

[Prof]

I wonder if the clutch isn\'t disengaging fully, or maybe your pilot bearing is damaged or starting to collapse. It\'s supposed to allow the engine to spin against the end of the gearbox shaft.
 
You could check the clutch is disengaging by taking off the four bolts that hold the inspection plate at the bottom of the bell housing and taking a look, but without taking the gearbox off and getting a small camera or bore scope down the end of the eshaft, you wont be able to see the pilot bearing. Mine had collapsed, and it was all but impossible to get the car into gear when stationary with the engine running.

[shifty biscuits]

im pretty positive its not related to the clutch.. it feels like an electrical/air issue rather than a mechanical dragging. the box and clutch all operate fine, not graunchy or hard to select gears....

[Prof]

There is a switch on the clutch, used by the ecu to control fuel cut to the rotors on deceleration, it\'s possibly something to do with that.

You could try shorting the switch or unplugging the connector from the switch (can\'t remember if it\'s open or closed switch normally, to simulate pressing the clutch pedal - if the problem is electrical, then it should happen again.

[shifty biscuits]

ok mate great suggestion, thanks. i will try that.