UK Auto Repair Questions?
Vauxhall Corsa 1.2 Excite 2011, 9,000 miles On changing gear engine rpm increases as clutch is depressed and engine comes off load before falling back as one would expect. Seems particularly noticeable from 1st to second and second to third gear. Car otherwise faultless and driven with care. John XXXXXXX
ear VauxdocThanks for your reply. However it's not helpful. The car has only just started to exhibit the problem I described. No other car I have ever driven, including other Vauxhalls, has ever increased the engine rpm on changing gear. Modern cars, using an electronic throttle, do not shut of the throttle as quickly as older cars in order to control the overrun as part of the pollution control process. That said, I've never experienced engine rpm actually increasing as the engine comes off load when you change gear.John
How can you claim this is a normal response? Stand by any road and listen to a car accelerating away - do you notice that the engine rpm rise even higher at the point of changing gear? You do not.
There is clearly a delay in the ecu shutting the throttle which momentarily causes the engine rpm to rise as you depress the clutch. This is obviously not normal. The ecu controls the rate at which the throttle closes but point at which that starts is the very moment you take your foot off the accelerator; not after you've depressed the clutch.