20XE revs sticking

[Tony M]

After going down my local dual carriageway the car is now constantly revving at 3.5k rpms. Any idea's why this is happening? :(

[Lewis.]

could be the idle control valve, or an air leak. what have you checked so far?

[Tony M]

I checked the throttle cable and that is good. I haven't checked for air leaks yet but I didn't think of checking because I know the pipes were in good condition?

[Lewis.]

they are only good up untill they leak, it might just be a loose clip letting something fall off, or a breather pipe rotted out and drawing in air. is the MIL on? is so flash the codes and see if its the ICV

[Tony M]

MIL? No ECU light showing when running.

[blue_peg_16v]

Take air box of and blow a load of carb cleaner down the breather to the icv it's how our local Vauxhall dealer used to clean em if it improves take it off and give it a proper clean

[breadstraw]

could be your throttle position sensor
mine was doing this, but couldn't get past 2.5k
simply unplug it and you'll be good to go :)
although bare in mind you won't have a rev limit at all, so be careful