happened to me almost every time.

The way I deal with it now is:

1. put silicone grease on the boot and the tb

2. remove the round plate from the arm that pushes the fuel distributor

3. with the plate removed you can easily push the boot from the inside over the tb with everything in place

4. put the plate back on

note: that works well on a M103 but on a M117 (your engine) the boot is longer and even with the plate removed this might not work for you

and its important to get the boot to seal tightly against the tb otherwise the car won't run

Thank you for your helpful suggestion!

__________________
Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)