What to do next? Engine Idle

5th January 2009, 12:38

Saxo 1.1i, 2000/W, 45k

Original problem was massively over revving (up and down) when at a stop and 'kangarooing' when driving.
I have changed idle control valve/stepper motor (reccomended by citroen after diagnostic) and problem stopped.

Soon after when at a stop (at the lights etc) revs drop untill almost cut out. This always happens after bout 4 mins of driving, never from the off.
Also sometimes i notice revs drop when i turn on electrics such as the rear heaters etc.
Changed the Lambda sensor, was OK for about an hour then started again.

Problem seems to be helped after the battery has been disconnected, but always comes back.

Could it be the ECU?? Any ideas?I know its a boring one sorry.

5th January 2009, 13:30

possibly the map sensor, start the car from cold with it unplugged and see if you still get the problem

5th January 2009, 13:34

agreed sounds like map sensor issues

5th January 2009, 13:38

I bet its the engine coolant temp sensor. Had the same thing on mine, replaced it and it was spot on

. When it does start revving on idle like mine did, on the right hand side of the engine there will be a green plug going into the engine block. Take the plug off the sensor and it should idle perfect then...

Thats what happened to mine anyway and sounds exactly the same, only like £10 for a new sensor too

.

5th January 2009, 17:45

Cheers for the quick replies.
Ill take a look at both.
Any ides where the MAP sensor is located? Haynes Manual isnt very clear!!!