Join Date: Feb 2007
Location: Gothenburg - Sweden
Boxer 16v - Idle advise needed!
Im actually pleased the way the engine is running, but the Swedish MOT-staff are not impressed.
The engine was oscillating between below 2000 - slightly above 3000rpm with a steady pedal when one tries to achive 2500rpm steady idle. I've had the idle valve off, cleaning it as good as I could and the sprayed some 5-56 in it before i had it attached again.
With the engine off it's possible to hear the throttle click-noise from the switch just as the throttles are about to open, which sounds all ok. BUT, when I moved the throttle switch so that it was on all the time, it was possible to keep a steady idle at, e.g. 2500rpm. This does not feel right, but it is running normally.
However, at the MOT it failed the exhaust requirements at 2500rpm, and it had the following readings (requirement in brackets).
CO 1,9 (0,3)
Lambda 0,94 (0,97 - 1,03)
So, it's running rich, but the lamda sensor is new (original bosch), so why is that? Should it not compensate? If I disconnect the air mass meter the engine is running very rough, and almost stalls. When I disconnect the temp sensor (to the motronic) the engine stalls directly.
Any thoughts or advices?
I think the next step for me is to buy a wide band lambda sensor, so i can see what's happening when I do different kind off suff. But advices are very welcome anyhow.