smax tdci intermittent starting issue

[stretch]

I have an 07 smaxx zetec tdci and last week it failed to start it would turn over for about 5 seconds stop then 'click' then turn over again (not sure if this is a safety feature to stop the starter from burning out?) I left it went back an hour later still the same, left it about half an hour and it started fine. It had a new battery last month, no engine management light on or current/pending codes stored. It also had a new clutch and dmf about 20k ago.

From posts i've read i've seen people mention the manifold butterfly flap? is there a part number for thus