Engine - Coil Pack
Older cars tend to have a single ignition coil feeding a rotor
on a distributor
which in turn makes contact with each lead feeding a spark plug.
Setting the timing between rotor and the cylinder compression point is vital to ensure smooth running.
The TT is controlled by its ECU, you have no timing to set and
each spark plug has its own ignition coil.
These are well known to fail and some implication in the build quality of these is in question.
If you car loses power suddenly and makes nasty noises,
chances are a coil has failed and
the ECU has shut down fuel supply to a cylinder to protect the engine and catalytic converter.
2 Coils are easy to access, but 2 coils are under part of the
vacuum systems so a few more bits
need to come out to gain access
Click on a coil or the Vacuum Pipes for a closer look.