Throttle Body Problems

[Tailor]

Ive got a bmc cda bolted to my engine, has been working with the car perfectly for about a year so far.
But now every time i start my car in mornings or after 3 - 4hour intervals the car just cuts out, i have to then warm the car up for about 3 mins until the temp of the car is higher.
Ive taken it to my garage and tested it with the computer and its say its the throttle body housing which needs to be changed, ive been quoted £160 fitted.
Has anyone else has the same problem or does anyone have any advice
All helps appriciated