Engine revving up and down on its own

[geo1903]

Hi folks. Mrs geo1903 is running a T reg 1.1 Saxo and has been complaining of late that the car `revs up and down on its own`. Obviously its not a sticky throttle cable as that'd keep it revving high/or low depending on where the cable was sticking.

Any ideas?

[Jack]

It'll most probably be the idle control valve. My old car (a T reg 1.1, funnily enough) revved on it's own, I replaced the ICV and it was fine. I got one for about 25 quid off of ebay.

[vtr_chris90]

This can also be the tps sensor, people always forget This one.
The tps when faulty can tell the Ecu the wrong readings I.e it will tell the Ecu the throttle is part open when it's not and the Ecu will then find an alternative to pull the air in because there's not enough coming through the throttle body, and that is the icv it uses to do that
Ive had that problem before on my car, diagnostics will be your best idea before going on a spending spree on sensors just guessing
When diagnostics are done sometimes both these sensors come up ad a fault. In which case you will be beat having them look at the data to spot any changes and false readings, cheap code readers won't do this you will need to go to a garage.

It can be the icv, but as I've said it can be other stuff, a cheap way of testing this is givin the icv a clean up first then see how you get on if the problem
Is still there then get diagnostics.

[GTuff]

icv all day this happended when i had my induction on mine