I would be grateful for any advice or suggestions on the following
problem:
Recently going down a long hill and going up a slight rise to a
roundabout,when I went to change down the engine cut out. The engine
started again no problem and off I went, However, since then, after this
the same thing happens at the exact same spot,. After starting it again
using a little throttle, the engine felt very gutless and weak going
along the next road followed by another long hill where it struggled for power
even downhill; whenever the revs fell the engine 'throbbed' and
struggled.
At the bottom of another hill I floored the clutch at a
junction, the car cut out again, and it was reluctant to start this
time. Finally got it going again, opened the throttle and got it to about
4k revs, anything less than this and the engine throbbed and cut out
again. After starting it again It then settled down and it ran fine the
rest of the way home, it has since done in this on 5 other separate
occasions, all at the bottom of longish hills.
The car runs *perfectly* the rest of the time, it's a 16 mile journey to work, it's fine on the way there, but on the hill on the way back it does it at the bottom of this particular dual carriageway 50mpg limit hill without fail usually

So far fitted new throttle body, new plugs and leads and a coil pack .Thanks