issue engine speed when AC runs, FI-engine

[Roger27TBB]

Hello,
when the engine is on temperature and i switch on the AC the engine speed
suddenly rises high up to 6000 rpm when i push the clutch pedal.
While driving the car gets faster automatically. This only stops by switch off
the AC.
Could it be a faulty full throttle cut out switch?
Where is it located?

regards
Roger27TBB

[FI Spyder]

The only thing I am aware of is the solenoid that bumps up the accelerator rest position to increase the idle to compensate for the extra load on the engine. Nothing to do with clutch or high speed. Does this happen at idle or when the car is stationary so you can see anything physically happening under the hood with the throttle cable? Failing anything mechanical that you should see, I would clean all connections with any thing to do with the throttle including ECU. Always as a last resort is to change ECU with a known good one. There were two (non compatible) ECUs an early one and a later one.

[Cobber]

I’m wondering if there is a short in the system that contacts when the clutch pedal is pressed, maybe a bad earth that earths back through the clutch when pressed, I dunno but there seems to be really weird going on and really weird stuff is usually electrical in nature.
Check the idle solenoid by disconnecting it, starting the car, turning on the AC and operating the clutch pedal.
If the problem goes away, you now know where to start looking, you may find the car stalls with the idle solenoid disconnected you may have to feather the throttle to maintain revs.
Not really a practical solution, but more of a diagnostic method.
What I find hard to figure is why it revs so high, the solenoid will be adjustable but I doubt that it could adjust that far and how it could be so far out. Maybe there is something wrong with the throttle mechanism.

I make these suggestions without being familiar with the fuel injection versions of our cars, as Oz spec cars are all carb versions.
But I base these thought on experience with other marques

[Roger27TBB]

Hi FI Spyder, hi Cobber,

at first thanks for your support. I have to check the accelerator cable first,
or as Cobber says the mechanism of the throttle valve. I will also clean the parts
of the mechanism. May be the air intake valve is dirty. The end of the accelerator
cable feels a bit to loose.
I will check the idle while running the engine and AC is stationary.

regards
Roger27TBB