I've read the recent threads on Intake mods, erratic tickover lambda sensor problems. Here is another problem to add to the heap and maybe some one can shed further light: My car is a '99 Selespeed with 75K on the clock.
I looked at the air intake and found that the top of the filter housing was not in place correctly... 1 screw with no thread and one sheared
completely. Not uncommon on this site! So much for the €260 spent on the last service! Looking at the throttle body and butterfly, it was covered in muck!
I cleaned the opening with a clean cloth to remove as much gunk as possible (oil deposits) and then sprayed directly into the butterfly as the engine ticked over holding the breather tube to the opening to maintain flow past the AF sensor. The engine dies if you dont do this.
After fixing the cover and cleaning the butterfly with a 1/4 can of carb cleaner the revs were high, 1500 to 900 approx varying up and down slowly. The revs don't fall back so moving off in 1 and 2nd can be very jerky. This has not improved.
I know some of you have spray cleaned the throttle and butterfly opening, could someone explain why the revs are staying up so high? How long before it goes back to normal... 400+ miles since. Where did you spray, engine on/off etc.
I might need new spark plugs and they've never been changed in the 50K I've clocked up. I should probably have a look at them. Might try the fuel cleaner additive today. Failing all that back to the dealer reluctantly I guess for a diagnostic check!