Opel Corsa Problem

kincaid

Hi All,

My friends 2004 Corsa twinport 1 litre petrol car has an uneven idle,
Its starts perfect but idle is up and down and when a diagnostic scan is done on it all comes up clear.
Its only done 49k miles from new

Any ideas or is it somthing not to worry about

Thanks

Jordan537

My corsa to was reading false readings on the fuel gauge. the receiver is under the rear seats, mine was loose and just had to be taped back up securely.

kincaid

hi, yes i think the fuel guage is not showing correct reading on this either but would this cause it to idle incorrectly

thanks

Jordan537

The idle is controlled by the IAC solenoid in the throttle body. What it does is; it controls the idle by allowing more or less vacuum (air) into the engine to speed up or slow down the idle speed. This may be gummed up, and in need of cleaning. Another thing that will cause this is a faulty temperature sending unit or sensor. The computer controls the IAC solenoid, and raises the idle speed based on the engine temperature. More for when its cold, and less when it warms up. Any vacuum leak such as a hose that is off, split where it plugs on, swollen to where it doesn't seal off around what its connected to, or collapsing, can all cause idle problems. An EGR valve that is sticking can make it do this too. Most of the time it will set a code in the computer, but not always, so if you have no check engine light that is on, then there won't be any codes to pull from the computer. I would vote for a vacuum leak as the most likely culprit. Many times a leak can be heard by listening to the engine area for any hissing noise. Find this, and you have found the cause. The second on the list would be either the temperature sensor, or sticking EGR valve.
Glad to help out, Good Luck!!!