Thanks again Vaty and Dirk. I just finished reassembling the carbs back on the bike per your suggestions. She started up pretty quickly and ran fine while cold. Unfortunately as before (even though I didn't quite realize previously) once the bike warmed up it started stalling (would not idle) again and becoming hard to start.vaty hat geschrieben:For my unstanding unfiltered air does not enter the carbs through the air vent hose.
The carbs are working like the venturi principle. So the carbs need an ambient air pressure to adjust the correct air and fuel flow.
When you plug the air vent hose, the carbs are adjusted with a static ambient air pressure. I don´t know what happens during, for example, different weather conditions with different ambient air pressure. It could be possible, that the carbs are not working correctly. Same happens during a drive from sea-level into the mountains. The actual ambient air pressure will change in this situation and the carbs are not working correctly.
So never plug this hose
Take care
Vaty
Dirk, thanks for the explanation, btw, I already have a copy of the shop manual. For example it mentions that to check the solenoid valve you should hear it click, which I could not. For the butterfly valve sensor assy I will be checking today as that should move/turn since that's it's function.AoS hat geschrieben:There are two different systems we have to speak about:
On the one hand there is the vacuum system that regulates how fast the piston valves rise, especially in gears 2 and 3, for the purpose of noise reduction. The solenoid, the sensor and many of the vacuum tubes are related to that system. The sensor also seems to time the ignition. Some say that you can safely remove all of this, but I'd keep the sensor and just get rid of the solenoid and the tubes. You can connect the tube number 5 (please check, I'm not entirely sure) in your diagram to the vaccuum side of the fuel tap and remove all the thin tubes, the solenoid, the vaccuum chamber and the check valve.
On the other hand there is the PAIR system meant to reduce emissions. But I don't know much about it since we don't have the PAIR on the German versions of the XF.
(The original shop manual has some very concise explanations on the carbs and the different systems. I could send it to you if your inbox can stand a ~13 megabyte file.)
Dirk
Thanks for the advice Dirk.AoS hat geschrieben:I'd just throw out all the unnecessary parts to reduce possible origins for the error. But I can't imagine that the vacuum system affects idling in the way you describe.
There is no temperature sensor, and the sensor on the butterfly valves just registers the position. Together with a gear sensor the information is used to limit the speed and level of the piston valve by bypassing ambient pressure to the diaphragm. If the solenoid has broken it shouldn't change much, this just disables the system. As far as I know sensor also times the ignition but the engine seems to run just as well without it.
Have you cleaned all the jets? Is the fuel level set correctly? Does the choke work? Is everything sealed airtight? Have you adjusted the idle screw? And I would check the valve clearance.
Dirk
