Just getting my 2003 car ready for MoT test tomorrow, but the idle speed is too high at about 1,400rpm, even when at normal running temperature. Oddly, the revs drop to where they ought to be (800 rpm) as soon as I depress the clutch pedal, but then return to 1,400 when clutch is released. The car has been garaged since autumn, so don’t know if something has stuck open/closed, or if it’s a sensor problem, or… Thoughts please.
Post script: As anticipated, the car failed the MoT test because the emissions couldn’t be measured due to the inability to achieve proper idle speed. Also, the emission testing machine apparently detected a small leak in the rear section of the exhaust (I didn’t realise they were so clever… in fact I’m a bit sceptical about this!!) at the entry joint to the rear silencer.
The garage mechanic seems puzzled, but suspects that it is a fault in a switch mounted on the gearbox (a clutch lever position detector, I suspect). There is an audible squeak when the clutch pedal is depressed.
Apart from this, everything else passed. It had new wings and sill repairs in December, which cost me £1100, so I really don’t want to have to scrap it.
Any suggestions very gratefully accepted.